I've never played Morrowind in depth before. I tried for a couple hours but it was too dated for me. That's why I'm helping with this project!
But I actually don't know a lot about Morrowind. Like for instance, is this landmass I circled called "Morrowind" or does the actual continent by itself (not including Vvardenfell and Solstheim) have another name?
Also, how much of the actual continent of Morrowind did Morroblivion have in game? Do we plan on bringing this continent into Skywind or just Vvardenfell and Solstheim for now?
Thanks :)

Morrowind is all of the
Morrowind is all of the purple on that map--including the island of Vvardenfell and the other islands off the coast. It's the name of an Imperial provence, like Cyrodiil (from Oblivion) and Skyrim.
The game Morrowind (and by extension, Skywind) only includes the landmass of Vvardenfell, the city of Mournhold (added in the first expansion, Tribunal), and the island of Solstheim (north of Vvardenfell).
Skywind is a port of the game Morrowind into Skyrim's engine, using Skyrim's updated game mechanics and balance. So it will include the areas in the above paragraph, along with all the NPCs, quests, items, etc. I hope that answers your question! :)