Whilst BAEF may have a degree of autonomy, I just don't see a MAN base happening.
BA's main priority is long haul on the North Atlantic and other key markets. In terms of growth, all the signs from IAG are that BA will be focused on rebuilding long haul capacity in the coming years.
Short haul aircraft orders for IAG seem very conservative and with BA still leasing out slots at LGW & LHR, it's not as if it's exhausted capacity in London. The brand recognition in the South East is stronger - watching people tap in and out on the Tube it seems that half of London has a BA Amex card.
Also, the last thing BA should be doing now is anything that distracts it from operations in London - hopefully this summer will confirm it has turned a corner.