- Signal has stated they'll withdraw from the EU rather than cooperate
- That means the app won't exist in the official EU app stores (iOS, etc.). Users will have to load the app on their own (which 95% of users won't do)
- Next, because Signal is no longer providing services, Signal's EU gateways will not be operational. Now your messages are encrypted, but I've no idea if your Signal connects at all, and where (Signal gateways in some Five Eyes country, perhaps?).
tldr; you're still leaking metadata, and now to a country that has no obligation to not track your metadata (your IP, when you sent message, who received message around the same time, etc).
My suggestion would be get a proper decentralized messenger rather than spend time on these workarounds of questionable value.
I always get down-voted for "shilling", so I won't even make any suggestions this time. DYOD!