Maybe incorrect to parallel LGW & STN regarding the Chinese carriers as MAG are approaching that particular market with a different perspective.
The pitch just as much concerns the East of England & the "Cambridge Corridor" other than just the London Market per se & have achieved large regional backing.
MAG have achieved success for MAN selling regionality to the Chinese & SE Asian market & will have the expertise/contacts & figures to succeed.
As mentioned though the numbers of new services at LHR/LGW must be eating into the number of services agreed/permitted in the latest bilateral.
Chinese carriers are naturally cautious with Western markets & no doubt the "B" word may make them doubly cautious until everyone can resolve where the pieces fall.