Look BA can not get rid of people just because they are on an old contract. They will not be paying for us to sit at home and do no work either. Qantas have done exactly the same thing and have crew on different contracts and the old contracts are still there.
You are all being frightened by a union that has got out of control. Yes of course BA would rather have people on cheaper contracts and as we leave that is what will happen. They are making huge savings from the new crew compliments and even bigger savings from Mixed fleet (and the union has helped make these bigger than ever)
What we should all do is get on with doing our job and show BA that E/F and WW can be better than Mixed Fleet with all our experienced crew.