I had a month or so delay on my car too because they ran of N20 28i engines!
Frustrating I know, but patience is requried. Believe me, the wait is worth it
Strange that he says he has an M5 with the same issue - that uses the 7spd M DRIVELOGIC DCT - completely different gearbox to the ZF 8HP used in our F30's.
Maybe ZF has had a fire or fault in their manufacturing plant or something.