Vulnerability also exists on iPad 12.1 and up as well as on desktop running 14.1 and up if running facetime app
Not anymore. Apple said they disabled the new multi-user facetime feature on the server side. More than 2 users in a session is what allowed the bug to work.
So I guess you are both right. Its still there until the next iOS update, but they prevent the bug from being executed on the server side.