Does Eastern still serve the French domestic routes (I think Rodez is still on, isn't it?)? If so, they would need an EU AOC.
Flybe, if I am not mistaken, no longer has domestic services in France (other than the Eastern franchise routes).
flybmi of ocurse has a ton of services from Germany to other EU member states.
What is Jet2's exposure to Brexit as far as post-Brexit intra-EU flying is concerned?