The changes are new, and there's a lot to be tested still, but I think Rakan and Thresh will be building the Ancient Coin now instead of the relic shield as they count as ranged champions according to the relic shield.
As for if it's still good... I pretty much only saw spellthief or relic shield previously.
Somebody with more experience probably has more to say about the subject.
I believe that it still is as viable as it was before (Well I use it mainly on Soraka and Rakan as Spllthief is rather useless on them, and whenever i try to use relic my adc gets angry at me for attacking cannon minions T~T)
I like to take ancient coin when I'm not sure about my adc quality. If you have to use Relic Shield, but the adc is consistently killing the cannon minions instead of letting you execute, it's a lot harder to get gold. So, I guess to me the coin is a default item; it's good when you don't feel confident with the other two.
There are still champions who benefit from it, while taking it out of bot lane isn't as effective nor is it nearly as good as it was with talisman, coin is still a decent pick on champions like Rakan and Soraka.
As a support main i believe Ancient coin and Relic shield are equal in gold incoming,im feeling like coin drop rate is high enough to dont be either overpowered either weak.Sightstone change has really helped all ardent cencor-redemption supports while they get their items a lot faster which has as result earlier power spikes.
I still believe Ancient coin will still be as viable as it was before since the changes affected all the support quest items. Like what Ronyk said though, the healing nerf to relic shield might cause champions like thresh to opt for anicent coin now but other than that, the support meta really hasn't changed.
As for if it's still good... I pretty much only saw spellthief or relic shield previously.
Somebody with more experience probably has more to say about the subject.