Either World Showcase will continue to be "based on real places, but with remotely-related IP thrown in," or these additions are the beginnings of a move toward replacing some/all of the real-world-based places with entirely fictional places (Wakanda). I think they'll straddle the line with the hybrid approach for now. With this approach, Wakanda wouldn't be a standalone pavilion, but rather an attraction/sub-pavilion within a proper pavilion themed to specific African-country/countries.
I would only hate a Wakanda boat ride in a Mozambique pavilion about as much as I hate Arendelle in Norway, which is to say-only a little. For some reason, I love the idea of Coco in Mexico. Not a big fan of Aladdin in Morocco, but Ratatouille in France somehow works for me.
For the record, I'm still a World Showcase purist at heart- I think the places based on real-life with some representation of authentic food, music, and culture is the best and most Epcot approach.