This game already doesn't accept any payments... :(
This deindexing seems to be separate from the mass ones and instead likely due to the fact that the gamepage has a content warning for SA, which is still being restricted more strongly even though this game is not NSFW. I have reached out to itch about the potential of reindexing it but it will probably take me a while to hear back because they are swamped with people emailing.
Thank you though.