I’ve got a long purchase history with my AD, and there are 9 people in front of me right now. My AD says they get 3-4 per year from Patek. Perhaps some of the people in front of me will cancel, change their mind, or have already received the watch from another AD they also put their name with, but it looks like it will be approximately 2 years before I get the call. This is in the US. Perhaps your friend will get lucky, but I tend to doubt it. This watch is becoming very hard to get. Tiffany in NY closed their order book on this one because it’s 5 years out based on the number of watches they get. They said 5164 is catching up with it, too.
Of course, your friend could always pay an expedite tax by paying above retail from a grey market dealer who has one on hand. Best of luck in your search.