You can no longer sign up for Messenger without Facebook account
People who do not have a Facebook account will no longer be able to sign up for Facebook Messenger. Facebook has also updated its Help Center page to reflect the change, which clarified that users will need to create a Facebook account to use Messenger.
28 Dec 2019 ... The user could just use their phone number to sign up for Messenger without actually signing up for Facebook, which allowed them to chat with ...