FYI, the reason they're replacing the HHG is it's very frequently broken. For instance, every time the ride slows down/stops to let mobility-impaired guests on, they must fully reset the HHG system to ensure it remains synced. Also, since the system itself breaks frequently. For instance, I went to Disneyland last June, and rode the Mansion at least 5 times. I did not get a hitchhiking ghost once. For this reason, they're replacing them with screens to ensure that it's always synced, always working, and every guest gets a ghost.