I remember the competition for the Jet Provost replacement quite well (BN Firecracker, Pilatus PC9, Shorts Tucano).
I'm certain Chevvron is correct, the FC was just a bit too slow to make the final grade.
I also remember the almost brand new "Christmas Tree" Tincano sitting long term in the "Dambusters" (CFS) hangar at Scampton. The word going round was that the ejection seats had been taken out and physically wouldn't go back in due to a bulkhead being out of square.
The best flying display I remember from those days was from the PC-7, rather than the PC-9. This display began with a straight run in at low level and completion of a very square loop. Very impressive and made a lovely noise to boot.