From what I read Granite were struggling to get financing together for whatever price Lufthy were trying to sell Regional for. If I were BA I would just sell it for a nominal price (or a price at least Granite can afford) as this would actual benefit BA - 1) they got a price reduction to take Regional in their BMI deal already 2) it would mean BA can offload quickly and focus it's attention on other matters 3) it means BA has fewer redundancy costs if it's only other plan is to sadly close it 4) it means BA doesn't get bad press this way (or less bad press at least) as jobs will be saved through a deal and the business hopefully could grow under leadership that wants to run a regional airline.
I hope a deal is made for regional and it's employees.