Hard to say. But it's a pressure campaign, and the people screwed by this, the steam ban, and countless others in recent years can certainly launch pressure campaigns too. Just a question of how well-organized it can become.
Viewing post in Itch has shadowbanned NSFW games comments
My point is those 1000 calls all have to reach the board directly to have a effect. To actually pressure them through call center you'll have to be able to overwhelm their capacity over an extended period of time. That's gonna take, 10,000 calls per day for two weeks?
If 1000 people send the CEO a message on LinkedIn there could be some effect.
Meanwhile, would you consider using some Japanese platform, such as DLsite? I think they are going to at least try to hold, for how much bigger and mainstream their industry is. But I don't know how practical it can be. They were not famous for being user-friendly to foreigners but there seem to be some improvements. If there is a sizable enough wave of immigration it may even entice them to be more open.
They do have an EN section, but a. They've been hit with a censorship wave already (though not quite as bad), and my understanding is it's much worse for the EN section. b. Yeah, not sure if I can even set up there as a foreigner, or how the payout system would work. c. I actually looked up the details on DLsite a while back and their rates are robbery. They take like 30%, even if you're native (for contrast, itch was about 7%, and that's all payment processor fees). Pixiv has their own similar crowdfunding/monthly payment thing, but that's ALSO censored now (although again, not as much as stuff in the US.) But believe me, I've considered, just probably not practical. If Japan unfucked their fees and gave visa the finger as they seem intent on doing, they could make a tidy profit being a haven for this stuff, but it's doubtful that will happen.