Avenger, as long as the UK follows EASA rules, you are probably right. But as far as traffic rights are concerned they, and EU airlines such as FR, are up !!!!! creek without a canoe.
At best they will get a EU-Swiss model. Unlimited 1st to 5ths, but no 7ths to 9ths. In other words, every FR flight UK - EU is going to have to originate in Ireland and vv.