The RAF could always incorporate an active reserve to put the needed crew in the right place. The guys that have left before the change of equipment and tactics can be effective in other areas of operations, guys less than about 10 years off the fleet would be able to brush up skills within a short period. Asking students on course to resign is asinine, the billy goats that engineered this shambles should be marched off the edge of the cliff instead. The students could however be relocated to other commonwealth forces that have short falls in crewing. Going back is not that hard, some of the words have changed, but the sky remains the same.
The guys and girls that left did so for a reason. Why would they come back to this shambles (with a paycut in all probability) again?