Signal is already well known to governments. In fact a few years ago there was a report in the UK media about how some governments used signal instead of official channels like email and did so because of Signals disappearing messages feature (ie making those MPs less accountable).

More recently, a Signal chat record leaked, between US national security advisor Mike Waltz, US VP JD Vance and others, regarding the ongoing illegal assassinations in Yemen:

https://edition.cnn.com/2025/03/24/politics/yemen-strikes-jo...

and it didn't leak because of Signal's security, but because an Atlantic maganize journalist was added to the group chat by Waltz.