Earlier quoted context omitted.
Another reason: all of the folks on that group chat have legitimate reasons to have contacts on their phone that would be outside government apps. Foreign leadership. Journalists. Etc. Signal is likely to be one of the main ways of communicating with those.
Using separate apps for government and external communication might have prevented the recent scandal.
It wouldn't actually. The contact in his phone (incorrectly added by Apple AI from a forwarded email) would be the same regardless which app he was using.
Instead, Signal (and this forked version) would have to do its own independent contact management, maybe based on in-person scanning of QR codes plus web-of-trust.