The word that came from the top last week is that BMED own all the slots and all the rights to the routes, so BA won't be able to operate them.
For example there are rights to 7 return flights a week between the UK and Baku, and BMED uses all of these, so BA could not operate even if it wanted to with out the agreement between the Governments changing.
BMED would not have gained any slots when BA handed over the route rights, BA will have used these slots for other routes. There was some clause or something that meant BA had a say on what happened if BMED was sold, but they let the sale to BMI go through with no problem. So there is no way they are getting the routes back in the short term.