As long as they don’t have different allergies or had biometrics recorded and assigned to them at the hospital it arguably wouldn’t even matter.

I’ve never heard anyone other than OP have any privacy concerns over Signal. Their encryption method is rock-solid, and they win the award for best response to a government subpoena

I can’t imagine having a manager like in this post. I had to get a few hours coverage for my on call shift to pick my partner up from the hospital for an outpatient surgery. Manager didn’t ask why I needed coverage but it just happened to come up. They immediately offered to get my entire shift moved without me even asking.