For those unfamiliar with the bug, basically all users had to do is make a FaceTime call to another user, and while the call is going through, they add themselves to the group call which would then activate the microphones on all devices, which in theory would allow the other user to be listened on without their knowledge.
By disabling Group FaceTime, Apple is effectively preventing the bug from being exploited. It is unclear if this bug can affect one-on-one FaceTime calls, but for now it seems to be limited to group calls. This is a massive privacy breach and hopefully Apple will have a fix in time. In the meantime if you want to be safe, you can check out our guide here on how to disable FaceTime on your iOS device.
It is a shame about this bug, especially since Group FaceTime is a feature that iOS users have been asking for for years, which it was finally released back in 2018 with iOS 12.1.