I love the effort to get a petition going. Unfortunately, I think there's a lot of important nuance missing from the petition. Itch has not said "Adult content is not acceptable," nor has Itch "effectively ended the sale of adult games on their platform." Not all mature content developers have received this (as stated in this thread several times, including by the OP), and many continue to be able to sell their projects on Itch.
That said, a LOT of adult developers are legitimately concerned because this is happening to some developers and the criteria used to select those developers have not been clearly explained to the community. Based on Leafo's posts on Discord, we understand it has something to do with risk to Itch and the developers' revenue sharing, but we don't have a lot of detail around what those "risks" are, nor do we know what percentage of revenue sharing would be acceptable.
It seems like this is a change in policy, from a lewd-games friendly platform that was willing to take a risk that developers would select 0% revenue sharing, to one that is going to require a certain level of revenue sharing to offset the risks and costs of hosting certain types of content. But the community didn't receive any notice about the change in policy or the measurements or standards it's based on, so we're a bit freaked out because we don't know what we need to do in order to remain eligible for the "collected by itch" payment method.
I think the claim that Itch is doing something they've explicitly said they're not doing (i.e., de-platforming all mature content) isn't going to be received well or leave them inclined to respond favorably to the petition.
JMO.