Are you suggesting that BA's UK domestics are profitable ?
I believe GLA/EDI -LHR are, also given the fact LCY feeds nothing and has the highest % of elites on the network and that BA offer services to LGW as well, they'd need to be in th eblack to justify the aircraft.
Seems odd to fly all of that at a loss! LGW and LCY have to stand on their own two feet as there's almost zero feed to long haul outwith the first wave LGW southbounds.