The big part of this story which nobody is talking about is the fact that the app is literally controlled by a bunch of “former” Israeli intelligence officers. Who now have what is arguably the worlds most valuable access out of anyone.
The US and many other countries have been buying Israeli surveillance tools for years or decades. I would hope that any message archiving is being done on an organization-owned server though.
There's compelling evidence that the messages all pass through TM servers before being archived.
https://www.404media.co/the-signal-clone-the-trump-admin-use...