I don't have personal experience with Toyota corporate works, but I do with Honda. I remember selling Hondas in the mid 1980's, and trying to get the factory to offer factory-designed cruise control kits to add to models which weren't shipped to the dealers with it. Honda's answer was, No, for safety reasons, we don't want dealers to install a factory kit, and we really don't want dealers buying aftermarket(available at the time) cruise control kits.
It's also why Honda and Acura, as recently at this Fall, still had a lifetime warranty on front and rear seat belts for all their cars originally sold in the U.S. if it was due to a malfunction or defect and if the belts were still in production.
My feeling is that Toyota operates no differently than Honda when it comes to customer safety.