Signal is actively working on other identifiers than a phone number, but can you cite proof that no phone will be required at all? I got the impression that Signal will still require a phone number at signup to do SMS verification, and only then give you a way to provide non-phone-number identifiers to contacts.

Eh, fair. I cannot cite proof, only note that every instance I've seen Signal promise this feature has been worded in a way that indicates no phone number would be required.

It is unfortunate that I don't see many from Signal on this forum, as it'd be nice if someone would just clarify this already considering the popularity of it as a feature request.

Not from Signal but the MobileCoin CEO posted this answer yesterday.

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>>The UK also has receiver verification. If I try to send to an account and it doesn't match the name I'm sending to, my bank will warn me. How do you stop impersonation?

A: Signal relies on phone numbers for identities. Other apps that integrate MobileCoin may have a higher threshold for identification.

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Reads to me like phone numbers are not going away.