They don’t have to integrate any older systems at all. Left alone they can and will do anything they want, and if that requires grounding older drones that can’t be retrofitted they’ll do it and say it’s for the greater good of the non flying public.
For the purpose of discussion let’s say there are 2 million drones being flown in the U.S., right now. Figure many owners have more than one drone so the number of people flying them is much less than the number of drones. With a population of about 320 million our drones and those flying them represent but a tiny percentage of the population and can be easily sacrificed in order to implement larger, longer distance, high revenue corporate commercial drones that need to be safely separated from all other traffic.
Unless the little guy rears up in his hind legs and roars the government doesn’t care about them. They contribute little or nothing to lobbying efforts and political action groups. Government does care very much about the big money players though as those are the people that line their pockets, give their relatives and friends high salaried jobs, and have a place in their corporate structure for government employees and elected officials when they leave office.