For example, on WhatsApp, use the whole 25 character limit for profile name. Examples:
Bob Moved To Signal.org
Alice MovedTo Signal.org
CharlieMovedTo Signal.org
Say Signal.org, not Signal, because they won’t know it’s an app.
Use your about section too. Same on Discord, Steam, Instagram, etc.
Its a LOT more anonymous, not slightly.
For the overwhelming majority of users phone number alone = no anonymity, then there’s the fact you’re relying on a corporation to store all your messages on their closed source centralized server…