Adding four random digits to people's names was a brilliant solution to two common problems with usernames (users wanting the same username and usernames of notable personalities getting leaked), and now they're just going to the exact same system everyone else uses with all of its attendant problems? Fuck off
Why not just use a friend code system where it's just a longer number or base62?
Actually the system they're switching to isn't that bad. Hopefully you can use anything you want in the display name so it can be funny like on Twitter.
That's basically what it already does with the Discord ID system, but that's primarily for developer stuff.