> They raised it just because it was relevant to the sun setting on the French Empire.
New Caledonia becoming independent would not have an effect on this though, the sun would still not set on France, as New Amsterdam and Wallis-et-Futuna are close enough to prevent that and very unlikely to leave France in the foreseeable future.
Yes and no. They're painting it as somehow legitimate and relevant. If you were seriously just enumerating possibilities then you could equally ask e.g. what if the Spanish decide to invade and reclaim their ancestral homeland?
If you meant the general point that some territories are disputed or revolutions can happen, you could have said them as such. It's pretty clear from your replies that you have an agenda in regard to this specific claim.
New Caledonia becoming independent would not have an effect on this though, the sun would still not set on France, as New Amsterdam and Wallis-et-Futuna are close enough to prevent that and very unlikely to leave France in the foreseeable future.