Canada never agreed to the "associate member" label -- that came from Ursula von der Leyen, and seemed to be ad libbed -- and just as we don't want to be the 51st state, we don't suddenly want to be a part of the EU instead. It was always about a different relationship that doesn't fall under any existing one, associate or not.

And some members of the EU are rightly saying "should we maybe define what this is before we're granting it?", and they're 100% right. If you basically handed over a lot of your sovereignty to a group and suddenly it's willy nilly adding new members in any form, without the consequences or costs, of course that is a problem for some.