Hi Studi,
The advantage would be that, in essence, even though he might start with two expensive AOCs, one only has around 300 pilots and one has 3000. He brands the smaller airline (let's call it BMI) as BA. All new aircraft, all new pilots, all new routes and any vacancies caused by retirement in "old" BA go to the BMI/BA new airline. All new recruitment on same will be on whichever contract IAG elect to offer (I think we can agree it would be markedly inferior to that enjoyed by either BA or BMI currently). "Old" BA will wither on the vine and die down to a point where we would be the 300 pilot airline and then I'd expect to just be put to sleep in an industrial sense.
Willy doesn't hold all the cards but he's got a serious advantage in the main and I think you're labouring under the misunderstanding that an airline can't offer a new contract to new joiners. Again, this may be a German law but it certainly doesn't pertain to UK employment. What one can't do is make someone redundant whilst recruiting for the same position on a different salary etc. But this wouldn't be that. We'd just be left to die of inaction. It's an admirably clever setup they've got.
There was nothing to stop Willy doing this in the last ten years other than the fact that IAG hadn't been set up and the manner of our incorporation was different. Also bear in mind that this is an opportunity being taken by the management to extract a pound of flesh - it's presented itself, he knows how valuable integration is to us, so he's attached a cost to it.
By the way, he doesn't need our approval. It's been extended to us as a courtesy to the regard in which our business relationship with our management is held and, I suspect, by how much the existing BA management want the BMI work/slots to be in house too for their own protection. You may think BALPA toothless but this offer of a choice is a direct result of that relationship.
I sense we're drifting a long long way off thread here so I suspect I'd best leave it now.