Even if we leave the EU, I doubt we'd be able to leave EASA without another string of years while we replaced their rules with ours and re-created National Type Certificates, National Flight Test rules, etc.
IF we separated - why would anyone try to get a new Type Certificate from little old UK? - I think we'd just be ignored!
The mere fact that EASA also has Office Managers who can't understand what their teams have produced is not a new thing in any industry. Idiots are in abundance in Management - I know because I are one.
Having said all that - the withdrawal of contact with the local CAA (or any NAA) is worrying...I suppose they will withdraw access to Mobile Phone Numbers next.