That's kind of funny. French people is the single biggest source of expats (if we ignore domestic helpers) in Hong Kong. Seems to be very common for French people to emigrate.
I remember seeing some article about French brain drain being extremely systematic now, especially among the better schools. Get free schooling in France, then leave.
Obviously I'm in a bit of a bubble (having done this myself) but a lot of my college friends left the country too.
Advice from a french expat in the US: do not. The image of France you have in mind does not exist. Go in vacation in Paris or in the south. It is a beautiful country. But do not move there.
Schooling in France is definitely not free. Public schools (the ones that are free) represent very little amount of the Masters Degree. Most are private schools and cost ~7-10k euros per year.
"Virtually free" can mean somewhere around 2000 Euros a year. A lot of people get aid (I didn't have to pay for my last year thanks to this). Plus most engineering schools don't really use textbooks, so you don't have much in extra expenses apart from a laptop.
Yes, taxes pay for this, but that was my out-of-pocket for schooling.
Seems unlikely that migrating from France to Hong Kong would be motivated by political reasons (unless you want less democracy). I'm guessing financial motivations dominate.
French tourists are very common in Japan, although I think it might be because of exposure to pop culture rather than emigration. They have an unfortunate habit of strip-mining retro video game stores and reselling everything at ten times the price back home.