Patreon's name just has more pull, more people know about it.
Subscribestar has less strict content rules, and even japans versions Fantia/Fanbox don't care if stuff is uncensored as long as its not hosted on their site, so he could even continue posting links to filehosts like he does with Patreon and it would be fine.
I agree, Patreon has the biggest numbers, so it would only make sense to open shop there, if you want the largest audience. It's just way too convenient to use, for seller and buyer alike. At the same time though, like you and
helenalove mentioned, a different distribution platform would be suited better for a game of this caliber with such "extreme" (what even is extreme nowadays) kinks.
Fantia/Fanbox is a good workaround in my opinion, but won't have the traction and user-friendliness like Patreon does, so that will probably reduce supporters/backing by some extent. I haven't followed this situation too closely, but if what you said is true about Patreon reviewing the situation with this game, there are two (maybe three) possibilities.
1) Game gets censored to hell, to play by Patreon's rules. Eventually lose some supporters.
2) All the focus is being shifted to Fantia/Fanbox, and they continue with their "vision" whatever that may be.
3) some hybrid of the two