I think you are putting the cart before the horse T5. If the inspiringly named 'Open skies 'goes ahead it is taking work out of mainline. BALPA have not objected to the airline starting, they simply want all the pilots on the BA master seniority list. If BA had no intention of taking work out of mainline then why would they object to such a zero cost option?
Sadly it looks like BA managements beligerence is pushing the airline to yet more industrial action, which could all so easily be avoided. Looks like none of us will be getting our huge 2% bonusses at this rate.