Some of the countries in these blocs did try to form bigger countries like the Sahel-Benin Union or the Mali Federation. However, I think that there has to be a change in how these countries were governed, or a uniting movement amongst the populations themselves, be it Pan African or socialism/communism, or cultural ties. I could see L'Afrique Occidentale Française (Fr. West Africa) somehow managing to stay intact, with some bumps and bruises along the way, but it requires stable governance, infrastructure, and education (both for men and women) for something like this to work. It would also have to work through the movements that arose from decolonisation, and the desire of minority groups to have there languages, cultures, and religions expressed and protected. Remember, within just FWA there is Wolof, Akan, Baoulé, Bembara, Malinké, Touareg, Fon, Ewe, Fulani, Hausa, Toukolor, among many other tongues and peoples brushing up alongside French, not to mention the religious divide between Muslim North, and Catholic South (with other things mixed in). That being said, West Africa kept economic ties, helped pioneer La Francophonie (the French Commonwealth), and even had a common airline company between them (Air Afrique until 2002). I would argue that in order for FWA to stay one country post 1960, there would need to be major changes in French colonial governance as far back as 1900. Perhaps start with a more desperate WW1, which allows Africans such as Blaise Daigne (who got elected to the National Assembly pre ww1, if you could believe that) to trade more rights for more manpower from the colonies. Additionally, have the Colonial Troops prove their mettle in way similar to how Canada, and Australia did against the Germans, and the French attitudes begin to shift ever so slightly. With more political rights, put some really compotent (and relatively less racist) governor generals at Dakar and Brazzaville, and you can get a shift in political governance, and perhaps investment in industry and education in the big cities Dakar, Libreville, Brazzaville, Grand Bassam, Bamako, Porto-Novo, later spreading out to the country side. Additionally, supporting some precolonial structures (which requires changes in French society away from Colonial worldviews and the Human zoos) would be to the benefit of creating unity (such as supporting the university at Timbuktu)
When it comes to Equatorial Africa, I know far less, and I'm not sure how it would work. It is a very large country with a long border, only the northern one being particularly defensible. With instability in Neighbouring Sudan, and particularly Belgian Congo (or Zaire, DRC, or Congo Kinshasa, take your pick) I'm thinking there's a high chance that it'll spread spread into FEA. Both countries run the risk of being pawns in the cold war, similar to how Congo/Zaire was, and the US or the USSR would encourage separatism if only to destabilise the enemy (and the same thing could happen in FWA too. Heck, Dahomey/Benin was communist during the 70's and 80's)
And of course if I'm talking about French Colonialism I have to bring up the giant elephant in the room...Algeria. France let go of it's colonies in Africa due to the political instability caused by the Algerian War of Independence (among many other factors, but I digress). Algeria caused a coup d'état, a bloody war, mass exodus, loss of prestige and loss of confidence in French governance. Since the late 1940's, France had already been rearranging and integrating French Africa in to citizenship and Metropolitan French governance style. However, Algeria was already part of France. The government saw it as much a part of France as Provence or Bretagne. Plus it had a lot of French settlers who wanted their privileges maintain at the expense of the Arabo-Berber majority. There has to be shift in the French handling of Algeria (which might need a POD in pre 1900, or at the latest the French-Indochinese War, but again I digress), in order for the rest of French Africa to have a chance at unity.