The load factors would not support your claim Bealine. Besides the move to LHR had much to do with passengers preference for flying from here.
Some of the route transfers to T/1 were once again to do with high numbers of transfer pax from that terminal, thus providing a better level of customers service.
T/3 was also used for some time for the Lagos flight and it may well be used next winter for additiional flights. One of the other reasons for its us is that it will be opposite T/5 and in the initial stages of its opening a number of the stands will be nearer T/3 than T/5 and the ground operation will be covered from T/3 ramp staff. FYI T/3 ramp staff cover the Finnair operation in T/1 thus giving them a dedicated team all the time (better customer service). So dispite what you may read BA is not totally devoid of having its focus on the customer service target. Rgds