plz1

Signal is E2EE. While it does use notifications, there is no meaningful unencrypted content in them. The content of the notification you see is decrypted on-device.

The “record” is a SMS verification code. All that will tell the government is that you registered for Signal, nothing else.

Signal doesn’t use SMS at all, once you have enrolled. The phone number is used to validate people and exclude bots, during registration. As others have noted, you can hide your number from other users, as well.

They can “request” it all day long. Signal doesn’t store them beyond the time needed to deliver to the end user device, and while (temporarily) stored, it’s encrypted in a way Signal’s service cannot read.