Quebec resident here, I just called this afternoon the CFP to ask if Quebec residents buying from outside retailers or individuals still have an OBLIGATION to register their non-restricted guns because the POSSIBILITY to do so does not make it and obligation. They transferred me to the Quebec CFO office.
Answer is: you can register on a voluntary basis which they strongly recommend because....no reason was given actually, but you are not obliged to and they say since they are no more laws or injunctions in place to sanction you if you don't, there is nothing a cop could do against it.
Of course cops not knowing their gun laws are plenty and the possibility they would go beyond what they legally can do exists, which is trouble even if you are cleared from any wrongdoing in the end.
In my opinion, the fact they still accept registrations is more politics than legal while the supreme court is pending.
Hope this clarifies, don't believe me? call them and post the answer here if its different, it would be interesting to see...