So over time, the number of new long and mid haul routes at Lgw will increase and they will stay there. At least, that is the way I see it.
TB
That assumes a static market, however it's more dynamic than that.
LHR airlines go bust or have to leave (Malev, CSA and the like) and that churn means slots do open up to long haul newcomers. LHR was declared full and closed to all newcomers in 1977, some thirty six years ago (!)