This has been flogged to death before, but why not another dance?
The Arab expansion stopped at Constantinople 717-718, that is where their army was broken. The full Anatolian campaign cost them around 200 000 men and about 1 200 galleys.
But ok, say that the Arabs win at Poitiers. They take their booty and head home, as they were doing when they encountered the Franks (why did you think they were so worried about their camp?), further raids across the Pyrenees will happen, perhaps a permanent settlement in southern France, but beyond that, nope. The Frisians have a good-sized Empire that controlled the north sea and will probably take over if the Franks are crushed.
When the muslims came to Spain they basically just had to knock the old Visigoth Kingdom over and had a large influx of recruits and settlers with the newly converted Berbers. The same situation will not exist in France - the Franks are a decently strong centralised Kingdom capable of fielding a very good pike/phalanx army, the Frisians to the north control the sea and also have a good centralised state. And the Roman Catholic Church is dominant.