I mostly agree with everything you said. However I wouldn't necessarily sacrifice Vietnam for the Maghreb. Maybe Burma.Of these places, I'd say that North America and Maghreb are the ones that are most in need of civs. Three civs for North America is really few while Maghreb is empty.
For Eastern Europe, the Byzantines are priorities, but not because they're from this region, but because of their historical importance. After that, I don't know if another civ from this region is a priority, even though I'd like to see Romania or Bulgaria.
Is there a possible civ for Greenland other than the Inuit? I don't know if we have enough resources for an Inuit civilization.
Do Australian Aboringenes allow them to be represented in electronic games? I've seen somewhere that they don't allow representation in video games or media in general, I don't know enough about them, though. If I were to include another civ of Oceania, it'd be Hawaii led by Kamehameha, but this in another round of passes, I don’t think it’s a high priority.
I'd be fine if Southeast Asia stayed with Indonesia and Khmer although I like the idea of Vietnam in the game, I would cut this to include a Maghreb civ.
I agree that Africa should have more representation, but Maghreb is the African region that is at the highest priority at the moment. I think Africa may have a civ on its east coast too.
If I were to say the top priorities of the moment, these are:
Native North America
Ancient Mesopotamia
Maghreb
Medieval Eastern Europe (Byzantines)
Portugal (not because it covers any region, but because of its historical importance and lack of a civ focused on exploration and colonization)
East African coast (Madagascar would be my choice)
Caribbean (not as priority as the regions above, but still a region that lacks civ. My choice would be Taíno).

But not for Morocco personally but some pre-Islamic Berbers.