the olympics is only one event, and only happens once every four years. the rest of the season, that happens every year, is much more important and doesn't have an olympic host to provide bikes. so there needs to be some procedure that catches motor doping at all the races, not just one infrequent race. The olympics is just going to follow the same procedures that are used for all the rest of the worldtour level races. and while the olympics might not care about keeping the rider's bike sponsors happy, the rest of the races do.
if riders weren't out there promoting bike brands and riding bikes provided by their sponsors, pro bike racing wouldn't be a thing.