Signal’s crypto doesn’t solve all problems (neither does wireguard).

For example, we built private information recovery using the first production grade open source implementation of oblivious RAM (https://mobilecoin.com/overview/explain-like-i'm-five/fog you’ll want to skip to the software engineer section) so that organizations could obliviously store and recover customer transactions without being able to observe them. The signal protocol’s techniques might be part of a cryptographic solution but it is not a silver-bullet.

I guess, notably, we never looked at NIST when designing it so maybe that’s the end of the discussion there.