" The EU stands to lose a hell of a lot more than the U.K."
Head in the sand stupidity. The EU will still have a functioning legal infrastructure for airlines and pilots if the UK crashes out. The UK won't have anything in place, nor will it have functioning agreements with its main partners. (Former partners perhaps we should say)
When will the Brexiteers notice that EU27 have been clear and consistent throughout this process - why would anyone think they're bluffing.