Disc failure unlikely???
One assumes (!) that it was not at take off power when it "vanished", and there is much less stress on most engine components at cruise power.
Maybe, but as on the trent 900 it was an oil fire due to a failed mismanufactured pipe that caused the disc burst on qantas. this could occur at any time in the flight in theory. i'm not saying its the same cause at all - just that it is a plausible explanation of sudden total loss of ac without comms - in theory - which the media is sort of implying is impossible.
It wouldn't explain the turn back etc. rumours.