Pain in the R's
Actually, the reverse is more likely. In the short term (2-3 years) slot sitting at the larger airports will constrain growth, the result will be more flights from regions. Recent announcements by both Wizz at Cardiff and Jet2 at Bristol are evidence of this. We know Wizz wants to grow at Gatwick and can't, the CEO has been clear why. Michael O'Leary has said similar about growth this week and slot sitting.
Longer term, a crack down on night flights especially at London's airports can be expected, as can some kind of resilience cap on movements to reduce the amount of extra routing an holding that characterizes ops at the busier airports. There is already evidence that this will happen (building back greener). The governments leveling up agenda will have an impact too, pushing the jobs and economic activity away from London into the regions.
Lastly, ten years from now most of us can expect to be driving electric vehicles anyway.