If, for arguments sake, we accept that BA cannot SOSR certain contracts only, and have to do the same to the entire CC workforce, offering the same new contract to all, then I am pretty confident that BA would not do it.
For a start WW as the voice of the board has said he does not want to reduce existing staff contracts in terms of salary, secondly, WW/BA have also publically said that the cost saving required has been achieved by reduction in crew compliments and the new contracts for new staff.
To avoid losing at any Employment Tribunals, an employer has to show a substantial reason - as BA have publically said the cuts in place now are sufficient, how can they prove a substantial reason for the drastic reduction that offering MF contracts to existing staff would entail?
Apart from that, CC would strike, and under this hypothetical scenario, I bet the currently non striking union moderates would also join the strike.
In fact, in this hypothesis, I doubt the VCC would volunteer either. At the moment they do so on the basis that CC have only been asked to make the same sacrifices that other staff have already made, but if CC are asked to make considerably larger sacrifices than everyone else, staff sympathies may change.
So BA would be facing genuine loss of flying ability, and loss of the
PR high ground. Not to mention absolutely appalling relations with their CC staff going forward, and creating huge distrust in all the other staff groups.
I think those that run the Union are probably aware of this, if they genuinely thought an SOSR to MF terms was a possibilty, they would have negotiated a lot harder. Ironically, in a way they are trading on BA's 'good nature' in that BA does not want to go down that route. At the same time, it seems the Union are allowing, even encouraging, ordinary CC to feel the fear that this may happen, as it strengthens the union members loyalty to the union.