I know that in general each platform has their own mosaic rules and makers sometimes struggle to make the mosaic just big enough to pass all their checks. This could be driving the decision, especially if they don't get that many sales from that platform. Also - for FANZA in particular they've been increasing the amount of censorship on their platform that I know some creators are getting pissed off at. I believe they've recently instituted a ban on loli content as well.
Damn. Didn't know that... that sucks. The game has a couple characters that might fit the "loli" designation depending on how you look at it. Maybe didn't want to deal with that.
Well hopefully I can find another way to grab it. If none of the kind-hearted souls here decide to share.