I just don't think state actors need to go that far. They can shut it down more easily than slowly trying to sink it through attrition.

And besides, if I were a state actor and I wanted to sink a program like Signal through such subversive means, I'd probably have someone start contributing to the project, and then start arguing in favor of bad UX choices; make it harder to use, not just unreliable, in favor of "security". Push it out of the realm of what a normal user could conceivably make use of.

That's the kind of long con I'd play -- play on techies' love of doing things on principle and for theoretical purposes, and general disinterest in UX.