Some news reports claim that the majority of the rebels already fled to the north.

I suppose the French way is to provoke exactly this, and to help the Malian army to reconquer the south.

North Mali tends to produce one revolt per decade, so there will probably be silence for years to come - and the usual suspects will understand that allying with jihadists provokes an avoidable intervention.
Next time, they will probably have learned and simply loot one or two cities, try to get some ransoms and withdraw without provoking Western crusaders and without questioning the integrity of Mali's government (which runs counter to French Africa policies).

Meanwhile, the jihadists may understand they cannot achieve anything beyond a certain threshold and will probably stay in the confines of their freedom of action; dominate most remote, economically irrelevant communities.
I doubt they're going to be any threat to 'us' there.


These northerner rebels did and do not enjoy elusiveness. They cannot hide among the people for long. Hiding against a Mirage 2000 may work, but when ground troops arrive some locals will indicate the location of the rebels.
You cannot be particularly elusive in a quite empty desert either. At most you can blend in with normal traffic and hope your enemies don't have the assets to fly along a limited quantity of routes and other spotted vehicle tracks.
The French even had Horizon (mothballed, IIRC), the British have ASTOR, the U.S. has a couple radar drones and JStars. It's basically a better exercise to keep an eye on such a desert region's traffic even without any improvisation with normal aircraft.