A brexit could have very far reaching effects on the entire industry, especially LoCo land.
Think of the Irish price fighter saying EI-registered aircraft in UK bases, some of its staff employed on UK contracts.
Or the Orange machine, flying G-registered aircraft in non-UK bases, their staff on EU contracts doing so (exception to its Swiss outfit of course).
Maybe nothing changes, grandfather rights, EASA compliance continued, etc, but can we all be sure of that?