Yeah, that is what happened to DLSite. It sells Japanese media such as hentai, so Visa & Mastercard put a universal ban on their products, no matter the category. It is a 1st Amendment violation IMO, since they are gatekeeping an entire culture.
I can easily see MasterVisa banning European or Canadian merchants for the sake of a Trump Regime.
I really hope that the EU introduces a global payment and banking system that is agnostic. I don't want to be under MasterVisa's thumb, and would prefer to keep the bulk of my money as Euros instead of American Dollars. Problem is, as an American, I can't readily use Euros in my daily life.
Here's hoping the EU can strike up a solution with Blue States, so that I don't need to ask Musk for permission to buy anything.