Facts:
500 hours on type required.
So Guy/gal who has gone to Eaglejet done 500 hours at Lionair is eligible to apply.
Instructor with 1500 hours, from two years of full time instructing. Doesn't get a look in.
Many of the airlines that use to recruit 1000 hour instructors now only recruit though CTC.
Consider the price of an instructors rating and the fact that most instructional jobs only pay 15 pounds per hour, then pay to fly schemes actually are for many the economically more viable option.
While BA may take on some experienced turboprop drivers I would suspect the majority recruited by BA in the next few months will be ex- Ryanair, Easy and Eaglejet, already rated on the 737, 320. So while BA may pay for the initial rating I suspect they may avoid paying for several ratings by biasing the recruitment to those with the relevant ratings.