Under the contract between bmir and bmi regarding the transfer list, the transferees have priority for recruitment to mainline over ALL candidates except cadets from Oxford who were sponsored by bmi. This agreement predates all current recruitment by at least 4 years.
However, this need not present a problem for the current mainline pool. The limiting factor as regards transfer numbers is the number bmir can release; given the fact that bmir has more aircraft arriving and can least afford to release the experienced pilots who have reached the top of the transfer list this number will not be large.
In answer to tonyic7's somewhat snide question, the transferees have all completed interviews and sim assessments; this means that, given their experience level, they are rather more of a known quantity and therefore less of a training risk than external candidates.