Patreon is at the scale where they would be exceedingly aware of this. One of the side-effects of the earlier 'not tying payments super tight to individual creators, but just charging patrons for ALL their committments' is that it let them aggregate charges in such a way that patrons were doing business with THEM, not 'NSFWCamGirl69', while still supporting CamGirl as the patron intended. The credit card company didn't really have a way to dig in and go 'prove you're not giving any of this money to porn creators'.
This changed, but Patreon remains a platform where it screens creators pretty well from the moral expectations of credit card processors (and governments? kinda? It's a very tough problem if they expect to do business at all in certain countries)
The question is more 'will Onlyfans be cut off from service by credit card companies': 'growing faster' is not useful if it's doomed. They have to also stay in business and maintain relationships with processors that have a record of showing intent to blacklist certain types of creation.