[troad]

To my knowledge, Signal makes a grand total of €0 in profit in Europe, or anywhere else for that matter, being a not-for-profit. It is not the purpose of a not-for-profit to grow exponentially. The Signal Foundation's mission is to ensure the continued existence of a secure messenger app. The people in charge of Signal take that mission very seriously, to their great credit.

There are already anti-circumvention mechanisms built into Signal to facilitate use in places like China and Iran, so they've shown no interest in compliance where that goes directly contrary to their mission. Should they be removed from the App Store in Europe, I imagine they'll work on making use of the EU's own push to open iOS up for alternative app stores / PWAs. (It's clear that the EU is unhappy with Apple's current take on compliance, so we can expect that to open up further.)

[account42]

Doesn't really matter what Signal does. If this goes through then the next push will be to implement the scanning at the OS-level for non-compliant apps. Or just to demand that Android and iOS get the ability to block apps on a government list even if installed outside the app store. Sure, a few hackers (and the criminals) will always have secure communications but you can't win the fight for widespread secure communication against the government's will with technological means.

[troad]

I think this seems like a fairly extreme and unlikely worst case scenario. I'd be sceptical about the EU's ability to actually implement something like this - there are limits to both what American companies are willing to do (e.g. Google leaving China), and what some of the more historically liberal European states are actually willing to tolerate from the EU level (imagine the blow to business confidence).

That's not to say that the present proposals aren't already bad enough.