Interesting that your first post was at 12.06 pm yesterday and your second post was at 11.04 pm yesterday. I see you went back in time and got the answer to your own question.....
Not so fast! Apparently, that agreement (still to be signed, as far as I know) restricts flights to the same number as last year. So if an airline has put on extra flights for this year or added new destinations, they won’t be permitted to fly.
Because of this, some (all?) airlines have added a “Brexit clause” to their T&Cs allowing them to cancel.
Sorry I can’t provide links to either of these, but I can’t seem to find them (and no, I don’t tend to lurk in dodgy areas of the Internet for my news: it was somewhere reputable I read them).
So, no issue with the Common Travel Area, but some flights may be affected.