“Usernames aren’t shared on your profile”. This means that while people can use your current username to start a chat with you if they know it at that point, people can’t see your past, current, or future usernames.

This link is not based on your username. Rather, it will contain a (random) UUID (not the account UUID, ACI, or PNI) called a username link handle that simply points to your encrypted username stored on the server. Since the username is encrypted (by your app before uploading it to the server to activate the link), it is likely the link will also contain a (random) key to decrypt the username (this key does not need to be submitted to the server). As such, this link can be created, updated, and deleted independently of your username. This means it may be intended for use as a temporary, throwaway link that you can share with someone without revealing your username or its hash directly (it will only be revealed to them once they look it up). When you delete the link, it can no longer be used to look up your encrypted username and hence contact you in any way and is thus rendered completely useless.

This is amazing. Seems like you can be “anonymous” to the one you’re talking to without revealing your username or your phone number. Though someone that can access the API to get the encrypted username via the UUID in the URL from the server will be able to decrypt the username using the key in the URL. Am I right?