Let me get this straight: Truth Social, and my outgoing email provider won’t let me use a VPN, but a suicide crisis center will. OK. Sounds fair.
Truth Social and your email provider are not operating by taking your phone calls, are they?
This was a internet-based phone call, and the person placing the call was behind a VPN. The phone operator isn’t going to see anything beyond the Caller ID info in that scenario, and with internet phone calls, the Caller ID info is whatever you want it to be.