I'm thinking that every year the main LCCs will cut routes which underperform on a A320 / B738. Normally it's because demand is more suitable for maybe an ATR72 or Dash 8.
Gatwick squeezed Flybe out because they had small aircraft. Presumably some airline somewhere will pick up that demand exists to/from London on these thinner routes which Luton and Stansted eventually will price out. An example might be Haugesund in Norway