I Do not think GM is going to allow the aftermarket tuning community any way going forward to defeat anything in the ecm for on-road usage.
I also know the Big Car Makers have been trying for a long time to force everyone to a dealer for all parts. diagnosis and repair, as it supports the dealers and their overpriced parts and labor if the funnel everyone thru that expensive door with no other choice but to use the dealer.
I know Porsche makes dealer pay $18K or so a year just to access PORSCHE Databases for vehicle diagnosis and even a simple service reminder reset often times requires an expensive trip to the dealer.
Its all about squeezing everyone for every last dime and making it impossible to go anywhere or do anything unless you go the dealer and pay thru the nose.
I wish they would do that private key signing, I bet it would cost $$$$$$$ MILLIONS $$$$$$$