This is an excellent question, and I have re read the narrative from the OP a few times. I conclude that since we are a nation with due process, you must be notified that you have something now deemed illegal.... After all not all firearm owners are watching these developments on an hour by hour basis. So for NR that is problematical as govt has no idea say who has a ruger mini 14. Now they might say notice is done by buying full page ads in major newspapers and having the media lapdogs list the dirty dozen to be banned every hour or so... I do a cut and paste of the relevant stuff from the OP. I hope my speculation is helpful
Before ya re read the OP comment, I will throw a wrinkle into the mix. It might be possible that they send the list of the dirty dozen or so to EVERY firearms license person saying... if ya have any of the firearms on this enclosed list, this is your notice they have now been deemed illegal.
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The CFP simply does not have the manpower tools or funding to roll out mass revocation of registration certificates. To contract that would take months and probably involve privacy violations. Either way the costs will be significant and immediate.
Slowly, eventually, the revocation notices will start to show up. They will allow 30 days for compliance. By now we are well in July, with the seizure notice effective in August. Just in time to ruin everyone's summer vacation and when the media will be hunting for some salacious political happenings in the middle of the summer doldrums. Gun owners everyone vowing non compliance. Others claiming its impossible to comply due to a lack of responsiveness from the CFP. Local forces will claim way too cash strapped chasing actual criminals to follow up. Municipal forces still haven't followed up with the half a million prohibited handguns that went dark after the last round of bans 20 years ago. This will make news, and in a bad way for government, right in time to kick off the election.
Every revocation notice is supposed to include instructions for filing a S74 judicial review. Every single person subject to revocation is entitled to review by a provincial judge. Now we are certain to lose that appeal, but that's not the point. First, filing the appeal buys you time, as I mentioned, the revocation noticed is on hold until the judge settles it. Second, if even 20% of affected owners filed appeals, we would be talking 50k to 100k court cases that must be handled by an already overloaded legal system
Hope this helps