Well they already allow credit card payments to their Playstore so it ain't that far before something like "Google Credits" would be launched for their own and their users use also.
It's unlikely they'll do though just from how they reacted to these crypto-related apps/videos so sudden.
They have admitted that it's just an error on their side to suddenly banning crypto related videos and imagine if youtube is going to release their own crypto coin instead of using conventional payment system. there are so many advantages they can achieve by using this coin like incentivizing viewers or even easily send payment from the adsense without the need to go through conventional bank and getting deducted by the bank fee.