I honestly really want it to stay ad rev from 100 subs. Creators with multiple comics ranging from 20-240 subs can actually make a decent bit before breaking 250 so raising ad rev requirements can really hurt some creators. And creators making anything that's not BL or het-romance on tapas (and specially those making comics that are really niche in general) are already struggling even though we usually get more page views per sub. I really don't think any decisions that could lead to the site becoming even less diverse is a good idea.
I think it would be better to either just only lower the requirement for tipping to maybe 100 or 150. Or if they're worried about bots keep 250 for new comics but lower it for longterm members.