The B788 was regularly scheduled last summer, so it was more than once or twice.
So tell me, if the B788 is optimal for PVG etc, then why 'waste' it on LHR etc too, when the B777 has the capacity and cabins, especially the B77W to operate said routes? Surely LHR is just as 'short' a route as MAN?
Also, you say MAN is not a key destination from OR, well, it must mean something to AA for it to have been operated since 1985 with just seasonal breaks while bigger cities have been cut.
Seems to me you are one of those who have a downer on MAN and feel we should get back in line as a regional airport that's lucky to have long haul.....