[be_erik]

By installing MDM you’re effectively chaining your security to the security of the MDM. The MDM gives you the ability to install arbitrary code via a blessed backdoor. There’s no reason currently not to suspect that anything said on that phone (signal or not) is compromised.

[croemer]

The MDM admin can do whatever the user can do (or more), sure. So yes the MDM admin can potentially read/hear/see stuff, but everyone knows that. That's not a vulnerability, that's by design.

The compromise is only wrt the admin. Are you claiming the admin itself is compromised? What's the evidence for that?