When will signal support signing up without a phone number?

Session messenger is a fork of Signal that ditches phone numbers for IDs and verification. https://github.com/oxen-io/session-android

It doesn't look like they'll get rid of the phone number requirement to sign up. However, they will enable usernames soon (probably within a few months). This will give you the option to hide your phone number if you want. Here's a demo from someone who compiled that branch: https://www.youtube.com/watch?v=g81mBMGw6fo

This is a good question and the move would probably precipitate a move towards an agnostic model and away from a mobile platform centric model. Let’s hope you receive a favourable answer

Never. And I said that from when signal was released, and anyone is using it for “privacy” is delusional, let me repeat that, any one is using ANY service that still uses a phone number as a mean of registration/ID/2FA/etc. and thinks that service is privacy oriented is a delusional one with false sense of security, I can go writing books on why phone numbers are privacy nightmare, bottom line: Don’t use a service that still a phone number to “verify” you. I second Session mentioned below, been using it for a while, still, would trust email+gpg more.