We need to recalibrate our costs a bit anyway. Last piece of staff work I saw that mentioned actual training costs put the price tag of producing an LCR(QRA-only) Typhoon pilot at over £10M, with a training pipeline that's a minimum of 4 years long.
There's your simple economics! A £250k FRI to retain a multi-role CR guy, a QWI, or a Flt Cdr is pennies considering your alternative is to spend 40 times as much, wait 4 years, and get a worse product at the end...!
Numbers may vary, but the same simple economics persist across all fleets, I'd bet. With Virgin recruiting, not only will that drag a lot of people away, but it'll generate holes at lots of other "stepping stone" airlines that people will fill too. Qatar Airways have even just announced a route to Scotland, to give them another foothold in the UK, haven't they?
I just can't really see many ways that manning works over the next 5 years.