This update gives Cho'Gath more health due to his 2 main mythic items: Frostfire and Sunfire, gaining more health overall, each increased by 100 making him a bit more beefy when you buy the items with a cheaper cost on Bami as well.

Besides those changes, the patch will not affect Cho'Gath majorly besides a couple matchups.

Cho'Gath is a heavy scaling and versatile champion that can be built AP damage if lacking, or built as he normally is seen, a heavy health tank that can tank the whole enemy team and take 1-2 people with him before death.
Being insanely strong in terms of tank power, AP and overall usefulness in the frontline, you'd be making a good tank choice in the hands of this monster of the void when he enters the field.

-Good Lane Sustain: Cho'Gaths passive gives him good sustain power to stay in lane and refill his mana. Combine that with Dorans Shield and second wind, his sustain power could almost rival Garen if smartly played

-Able To OneShot Squishies: Full tank or AP, you can oneshot squishies insanely easy thanks to your ults true damage power

-Useful even behind for a carry tank: Thanks to Cho'Gaths ultimate, even being behind isn't a full setback. His ultimate keeps him scaling allowing him to still be a useful tank against enemies in the frontline and providing good CC as a backup as well for his team

-Very hard to kill and easy to use: Once the Mid-Late game hits, Cho is a monsterously hard champion to kill due to how tanky he can get. Even as an AP Cho'gath, your tank power is still there making you capable of helping your entire team have to worry less about being killed as long as you're in the frontline with your CC and beefy power.

-Weak Early Game: Level 1 his E does alot of damage, but after using it you don't have alot to save yourself pre-6. You don't do a ton without your poke or sustain

-Enemies can kill late game if alone or don't stack: Cho'Gath NEEDS his stacks to be beefy and stay alive. Once the late game hits though while he is super beefy, without a team to back him up, he doesn't guarantee himself a win in the fights he's in meaning he could still lose a 2v1 if he isn't given help soon.

-Max Health and True Damage Champions Melt Him: Champions like Vayne, Fiora, Gwen, etc who rely on your health to do damage easily counter you in the longrun being able to get you out of a fight fast, making your tanky power near useless

-Very Weak Engage: Your Q is your only way to close gaps, but without it, items or flash you can't get into enemies faces so that just leaves you sitting there being kited without much of a way to get in the action.

Grasp Of The Undying is what makes Tank Cho'Gath get his tank power up even more. Giving you 5 health permanently once you hit an enemy as the charge is ready, your health will keep scaling throughout the game.
Demolish scales off your max HP when the charges are full and you attack a tower. By the time Late game hits, you're gonna be one shotting towers as you'll at late game be between 6k-8k health, so you'll be getting rid of towers insanely fast
Conditioning helps with your tanky power giving you Armor and MR after 12 minutes, so you have more tank power with this.
Second Wind is a good alternative against heavy poke champions as it will provide you with more sustain, giving you plenty of chances to heal up even more than with the sustain you'd already have passively
OverGrowth is another tank rune that helps you gain more health along with grasp and your ult as time goes on, giving you more HP in the longrun and raising your health to make you much tankier
Cheap Shothelps you do more damage in the early and later stages of the game, letting you do true damage to anyone with impaired movements. Your Q knockup and slow and your E slow will help proc this for increased damage
Ultimate Hunter is a heavily good and viable option for Cho'Gath. It lowers his ults CD by 25% when all stacks are collected, making your ult come up faster and more frequently for fights and executing faster.

Alternative Secondary Runes
Presence Of Mind can be a good mana sustain alternative if you'd prefer not to go domination, as it will keep your mana topped off along with your passive to make sure you run out of mana much slower
Tenacity is always useful for tanks to keep moving and providing cover for your teammates, in this case, it will make sure Cho'Gath can get in for the executes, stay stunned less, and keep his CC going for his teammates.
Manaflow Band helps to raise Cho'Gaths mana bar, seeing as how he has a low mana pool with high mana cost abilities, so he'd have more in the longrun late game for himself to keep his abilities up.
Transendence is just a very good way to give your already short CDs even shorter ones so that you can keep spamming your abilities, and even lowers your ult CD slightly as well

Arcane Comet scales slightly off AP and provides poke with your Q and E, giving you more poke damage overall
Manaflow band is good for giving you mana overtime, and gives your mana pool even more to work with at a lower risk of running out sooner
Transendence will provide your abilities with faster cooldowns for faster output of damage and your abilties wont be down as long
Gathering Storm will give you scaling damage as the game goes on, making you hit much harder if the game continues to go on as long as it does, making your scaling better
Cheap Shot makes you do true damage against anyone who's impaired, so knocking them up with Q or landing your E on them will make them take much more damage than they would before hand with your AP abilities
Ultimate Hunter lowers your ults CD by 25% at full stacks collected and will let you stack it much faster along with CD items and transendence

Alternative Runes
Nimbus Cloak will give you ghosting and movement speed for 2 seconds, making it easier to close the gap on enemies you hit, or at the very least lets you keep up if they seem to be faster
Scorchis good for extra poke damage based off level, igniting someone for a very brief period and giving extra damage poke

Carnivore is Cho'Gaths passive that is the reason his sustain is so good especially for lane phase, as it grants him 20 - 71 (+2.83 each level) Health and 3.5 - 7.75 Mana (+0.25 each level) making his sustain get better as you level
Rupture is Cho'Gaths Q, and his main gap closing/CC ability that you'll end up using the most out of his kit. It can deal 80-300 damage scaling off 100% AP making it his strongest AP build ability and one of the most annoying things to handle about Cho'Gath, as it also acts as 1 of his 2 slows
Feral Scream is Cho'Gaths second best CC ability next to Rupture. Silencing the enemy between 1.6-2 seconds off level also dealing 75-275 damage scaling off 70% AP, it isn't his most damaging ability but arguably is his best CC ability with his knockup
Vorpal Spikes is another CC and damage ability Cho'Gath has, dealing 22-70 damage +30% AP adding 0.5% per feast stack to the damage, it can scale easily well with Cho'Gath as well as he scales in general. Each spike attack also slows enemies by 30-50% decaying over 1.5 seconds and increases his attack range slightly as it travels through enemies.
Feast is Cho'Gaths main scaling tool through the entire game. Dealing 300 / 475 / 650 (+50% of ability power) (+0.1 per bonus health) true damage to enemies, it scales off his health and his AP insanely well, making it constantly scaling with his own health and power. Each stack he gains off of Feast gives 80/120/160 max health off level. Only 6 stacks can be gained from minions and non-epic jungle monsters however, but is unlimited off champions and epic monsters like dragons, rift and baron

Cho'Gath is an excellent scaling Tank and AP champion. Even though he has some downsides like every champion, the mid-late game makes up for that with how powerful he can become with time and effort being put into his kit and learning him.
He's easy to learn, easy to master and one of the most underrated and best tanks the game has to offer.
Hopefully after reading this, you have a better grasp of Cho'Gath and understand what he can bring to your team and the game itself.
Thanks For Reading!