Funny enough, they mention moving to ProtonMail which is at least based out of Switzerland. It makes this whole chain a bit funny, but I don't blame the commenter for not breaking down every service the OP talked about and the OP did shorthand it to "Migrating to the EU", so fair enough.

Servers of migadu are in france actually

Yeah, you are right. It's a bit buried in their docs.

Didn't proton fold like a wet napkin when they were asked for information about their users? What I mean is: Switzerland as a whole is probably the wrong metric...

These are also political decisions and the EU is much more powerful politically than Switzerland so if your adversary is the US and they're willing to use lawfare or more than you should probably go with the EU and not Switzerland. Germany is considered one of the most robust legal systems for privacy.

But there is always risk no matter what you do.

Switzerland - as well as EU based providers - have to comply with court orders. And the EU as well as Switzerland issue court orders upon request from friendly foreign states ("Rechtshilfeersuchen" in german) - such as the US.

Wasn't Proton launched as a "your data is encrypted at rest, we could never access it without your consent"? The implication being that even if they received said court orders, they didn't have anything to give. Am I misremembering that?

They encrypt your data insofar as your email, files, etc. but that doesn't mean they don't have information potentially useful to the authorities. See the recent headline where they revealed a user's payment information allowing them to be identified.