Moroccans were definitely considered for TAR, but they didn’t make it into the “final round” since there are so many overlaps with the European design culture (and history). It really sits at the crossroads between the two civ styles. That obviously didn’t make it a 100% fit for the African culture and for the DLC we really wanted the civs to be distinctively different from European civs. So due to this Moroccans were never cut or started.
With that said it is still a very interesting civ, however it’d be made, i.e. as a more African or European civ blend with elements from the respective other culture. If the game actually needs a Moroccan civ is a good question, since there is already so much there. Barbary Pirate scenario civ, revolution, African alliance, mercs, Berbers, etc. Thematically one could argue it’s notably covered already (though a main civ is always something else). Contrary to widespread belief existing content wouldn’t actually make the development of a Moroccan civ easier, since we can’t just rip all this content out of its embedded place within the live game. We’d actually need to come up with work-arounds, replacements, etc.
Hope that gave you some insights! 