Why would sephardi jews leave North Africa, especially Morocco? They have more in common with the local muslims than with the other jews. Also the zionist movement was always seen as anti-jewish by them and too european.
The Maghreb wouldn't be the place it is now without it's 5 million jews. Their economic and cultural contribution post WW2 was and is big.
Although Jews in the Maghreb are closely integrated with their surrounding communities, religious minorities have tended to have greater rates of emigration than not. Lebanon's diaspora started off as being overwhelmingly Christian, for instance.
In the specific case of Algeria, say, the French colon population has been inevitably dwindling since independence. They still have a place in the country, but French citizenship is still more valuable than Algerian citizenship. Many Maghrebin Jews have followed them, moving to France or Canada.
If we do see an independent Israel formed at the expense of Palestinians, I think we would see a dramatic worsening of interethnic relationships everywhere. Why wouldn't Arabs everywhere identify with Palestinians? Why wouldn't Jews identify themselves with Israel, or much worse, find themselves attacked because they could be alleged to have links? We could see a dramatic emptying out of Jewish populations throughout the Arab world. Even worse, this might extend to other populations, like the French of Algeria.