some early T/As ex LHR will not be manageable with a 3 hour T1-T4 transfer window. At present it's possible to make BA98 (dep 1155) with the 0730 departure from ORK. With an 0845 dep time that and some other connections will be impossible.
I heard somewhere that EI is moving to T5 with BA. If they do they won't need such a long transfer window. However I'd have to agree that the new timetable won't be as good for connections as the existing timetable. It may result in more people transferring via Amsterdam.