I've never seen this out west before (I'm in Alberta), so my guess would be that it's related to the sovereignty movement [0] rather than some broader grassroots movement to join the EU. But I could be wrong here.
I don't think it has to do with the sovereignist movement but I could be wrong too. It could be related to some relations between Quebec and the EU, especially francophone countrys?
[0]: https://en.wikipedia.org/wiki/Quebec_sovereignty_movement