Is that really the case? Per https://www.bitsaboutmoney.com/archive/money-laundering-and-... you can be pretty much completely debanked for only a couple of SARs/STRs, and it doesn't seem particularly hard to have one filed against you.

Ah, yes, the classic 3-2-1 method: three accounts in two different countries, one of them being an offshore. Yeah, I’m doing all that (not the offshore part... at least not yet).

Are you a resident of multiple countries?

Don't have to be - fintechs like Revolut, Wise, N26 are based in different countries, but service customers in a decent chunk of Europe.

and you can get debanked from all of them in the same incident.

The "incident" has to be pretty severe for you to be debanked in multiple EU+UK countries. Little less than terrorism would do it (I was going to say coup attempt might, but the Catalan leaders who tried to illegally secede from Spain didn't get debanked, so probably not).

Remember that Germany considers not liking the Gaza holocaust to be terrorism, and has issued Schengen area bans against EU politicians for this crime.