It would hardly change anything, as the
CFA Franc is pegged to the Euro only because the latter is the French currency.
If the Euro were to be abandoned, they would simply revert to being pegged to the
French franc (which, according to poll, a substantial fraction of the French people regret) as the CFA Franc is guaranteed by the
French treasury only, not the
European Central Bank.
And the same goes for the
Comorian Franc.
A big problem about the Euro, is that it was built around the
Deutsche Mark, which was one of the hardest currency in the World, reflecting the policies and the economy of Germany. The others "big players", namely France and Italy, have on the contrary a long history of inflation, due to their economic, social and political settings.
So at the end, a weakened Germany simply cannot hold the Euro by itself, while the other major members are either large inflationist countries, prosperous but very small countries (
BENELUX, Austria, Finland), and relatively large "developing" countries (Spain, Greece, Ireland), plus all the new members, which economies are far form being close to the German one.
It's no wonder that the U.K. , Denmark and Sweden stayed out of the Eurozone, and kept their own currencies. Why join an unsustainable hard currency when it's held only by one large economy, dragged down by large inflationist economies, and will be shaken by lots of developing economies; when your own currency is already hard enough?