“If you use Signal, your phone number will no longer be visible to everyone you chat with by default.”
Signal now hides your number from anyone who does not already have it saved. Usernames must end in two or more numbers, and there is no searchable directory of them. The default for who can find you by number stays “Everybody,” which is how Signal has worked for years. Signing up still requires a phone number. Signal stopped showing your number to strangers and kept collecting it anyway.