There are five things that come to mind from the antitrust lawsuit against Apple
Apple has been accused by the US Department of Justice (DOJ) of unfairly limiting competitors like WhatsApp, Signal, and Facebook Messenger. The DOJ said Apple also limits third-party messaging apps like WhatsApp, Signal and Facebook Messenger in comparison to iMessage. It added that Apple doesn’t support RCS to make cross-platform messaging better and third-party apps would still be banned from incorporating it even after Apple adopts it.
You will be able to share a usernames with Signal, instead of your phone number
Messaging app Signal has added a new feature that enables users to create a username in the app. Users will be able to generate a QR code or link to their username after they create a username. Other users will be allowed to claim their previous name, even if you change your username whenever you want according to the FAQ page.