I once saw Neil Patrick Harris at Disney and he was with one of these guides. He had his husband and kids with him. I think celebrities like him it's probably highly suggested they get this service (although he was there filming a Christmas special so it was probably free)
It's a person to take them from place to place and they completely skip the queues. I also think it discourages people from asking for autographs or pictures. I would think it would be so annoying to be bombarded with fans when you're trying to enjoy a holiday especially if you're a celebrity who doesn't post pictures of your kids faces for privacy.
Normal people can get these tour guides as well I think it's about $6k for a day or some stupid money. I only know about it from Disney Food Blog because it's my guilty pleasure to watch their videos on my lunch breaks
Rob Becket went to Disney recently (talked about it on his podcast) and said that no one in America knew who he was but from time to time a British person would recognise him and he'd have to explain to Americans why he was famous.
I'm American but I've lived here for 8 years and I feel like I've never met anyone that would know Tom Fletcher by name?