Sometimes they do
there’s a little Powerpoint presentation all about it.
Unless I am misunderstanding the term, shelf company is one that has never traded (société préconsitutée) as opposed to a shell company (société coquille vide) which has traded in the past but has gone dormant.
The OP clearly has a specific plan in mind, I think the main thing to be aware of is that in France a shelf company has a very short shelf life because normally after two years with no activity, companies are struck off. You couldn’t for instance buy a company now and keep it on ice for a few years until you are ready to start business.