It won't that's my point. The hassle of being co-located in T3 with Oneworld partners who supply a handful of daily connnections and mean other passengers have additional screenings for domestic flights is outweighed by the benefits of AA moving (back) to a proper long haul facility. They're going to bus AA passengers to T1? Outwith hubs and focus cities, of which MAN is neither for this Alliance, co-location often sees little benefit.