Do you really think BA are willing to give up on virtually all non-London based UK TA pax Frank? Because EI are targetting these pax big time ATM.
I think from every angle EI are a great buy for IAG, either to protect the LHR slots, absorb them, or use DUB as an outlet valve for the UK regions as has been suggested. Would it be better for EI than continued independence though is questionable, since a decent chunk of their TA pax, which is their moneymaker atm, are coming at BA's expense. David and Goliath of course, but the little bit of business David is taking from the giant is crucial.