I'm more concerned with the overreaction - perfectly functional aftermarket parts being rejected because "they're not stock"
I'd struggle to believe this will be an issue. Nobody is failing a car because it has a MOOG ball joint instead of an OEM one. Nobody is failing a car because it has a 12" section of exhaust pipe that was rotten cut out and replaced with another 12" section of identical sized pipe instead of unnecessarilly replacing the entire pipe, so long as the weld is good and the pipe secure. Nobody is failing a car because it has a Monroe shock absorber replacing an OEM one. Nobody is failing a car because it has a Canadian Tire CV Axle shaft replacement.
It's just not going to happen. Aftermarket parts are virtually a defacto standard in auto repair for any car out of warranty and this change isn't going to suddenly wipe out the validity of the aftermarket.
as such, small shop owner decides to hell with it. I can fill those few hours of inspection time with another handful of oil changes and avoid the hassle.
It takes a lot of $49 oil changes to make up for the easy profit made from easy money jobs like brakes, one of the most common things that cause cert failures. I had my wifes Volt in a few weeks ago to get a broken wheel stud replaced and it was "suggested" that it needed brakes on all 4 corners because of course, EV = Regenerative brakes = Mostly unused rusty rotors. The quote was over $1000, of which I know for a fact the profit is probably in the range of 60-70%, having done brakes more than a few times myself in the past.