I believe that the biggest problem the devs are having is that this message being sent makes the change a fait accompli. There's no warning, no indication as to something that could be changed to avoid this step - they go from being fine as far as they know, to being prevented from using itch as they have been for years, in some cases. Content that was completed over a year ago, if not longer, is no longer able to be sold.
If this is because the dev theoretically violated the TOS of one or more payment processors, then the devs involved would probably appreciate knowing exactly what said violation was. In the PayPal TOS, the only thing straight-out banned is obscene material. And the judgment on what is or isn't obscene tends to be subjective (as a Supreme Court Justice said regarding one case, "I can't define pornography, but I know it when I see it.")
For quite a while now, Patreon has not allowed content with incest on their site. That's frequently been dodged by changing relationships (mom becomes landlady, siblings become roommates, etc.). There's at least one VN I can think of on this site that makes little to no sense, unless you mentally translate these relationships back to what they "should" be. In many cases, such VNs are constructed so that a simple script can be added to change these relationships to incestuous ones. If that sort of thing is causing the problem, then similar solutions could be applied here; the dev would just need to know that.
By not providing such information (which might be provided to itch), the devs are left with a situation where they can't get around the problems - both because they aren't given a chance, and because they wouldn't know what the issue was.
While I realize itch is a small operation, they presumably use the services of lawyers (something most devs wouldn't think to do, even if they could afford to). The refusal to provide details may well be something that comes from lawyers. However, I would tend to think that knowing that a dev's content may violate the terms of service of itches payment processors, then telling devs to set themselves up to use those same payment processors for that same content is deeply unethical, and could be borderline illegal (it could be construed as providing bad legal advice - telling someone to do something you won't do because it might violate a contract). Note: I am not a lawyer, and I've never played one on TV, but I have seen almost every episode of Law & Order (et al.)
I'm not saying any of this is contrary to itch's stated policies, of represents a specific change to those policies. However, it does seem like itch policy may be being enforced more strictly. I believe it would greatly help the developers if itch could:
- Explain what has caused them to terminate the dev's ability to use itch to handle individual payments and sales tax/VAT/whatever on same;
- At a minimum, explain that there are explicit reasons why each dev has been picked out (even if for some reason itch can't divulge what those are);
- If there is a common set of underlying issues that can affect devs, publicizing what those underlying issues are, so that devs who may not know they may be violating TOS get the heads-up, allowing them to try to resolve any such issues before they become an actual problem;
- Consider signing up with a payment processor that doesn't put the same limitations on the content; and finally
- Consider requiring a minimum share percentage, if only on content marked NSFW. Not a popular move I'm sure, but if devs with such content place a heavier burden on itch, that has to be covered somehow.