it does technically mean CX now operate out of 2 terminals given the codeshares with BA.
I think for the few peeps flying HKG-MAN-LHR on days where LHR availability is stacked, they can suck it up rather than try and get a B77W out of the old domestic pier.
although BA used to fly a split load on LGW-MAN-ISB from 44 on the B744 as I recall.