BMI pilots would have a problem with a Virgin takeover because there wouldn't be jobs for most of them! Virgin would not suddenly buy tens of longhaul aircraft to absorb the BMI crews while reducing the shorthaul fleet. There would be some who would be absorbed, but not many I fear.
I think the scenario would be far more like this: take as many LHR slots as Virgin needs to effect its near-term plans. Sell those slots that can't be useful in the longhaul picture. Sell most of BMI's physical assets. Retain some shorthaul aircraft, crews and slots to cover those routes which have a large percentage of Virgin transfer passengers and are profitable - if there are any that fit this description. Examine (and probably reject) the possibility of turning the rump of BMI into a low-cost operation, possible in concert with Virgin Express (BMI Baby is unlikely to be part of any merger/takeover and will be sold off in its own right). Anything remaining would be disposed of - aircraft, leases, slots (with a caveat that they must be returned if Virgin needs them) and, most significantly, PEOPLE. Virgin is not a charity; it's a very hard-nosed commercial operation. It only wants BMI for what it can use to make a profit - and your workforce would, for the most part, be disposable.
This is a 'worst case' scenario, but I think it's not too far from what was being considered. That's why I think you should be glad it didn't happen!