the thing is..... they need the pay methods to work, and this initiative is treatening ALL itch's and Steam trasactions, so they must comply or they would be immidiatly shut down....
that's the mess up thing... it's a private congregation creating censorship unfunded by any laws (that I know of) and since they are basically a monopoly they can do this and no one can say "nah fuck it... I'm i'm ok not being payd anymore"
what they're promoting? More Piracy....... Ironic
that being said I do belive that some regulations need to be made in NSFW and Erotic games.... but this is not regulation...
as the oficial post on itch.io they're saing that they are adjusting the terms and will re-index the adult/erotic once this new terms are out