Given the size of Bethesda's Morrowind and its handcrafted content (compared to the randomness of it predecessor, Daggerfall) it's no surprise that some of the content didn't make the cut. If you'd like to see what the developers discarded, a new mod for the GOTY version brings back a lot of it. Like, a lot.
The mod, called Morrowind Uncut, can be downloaded from Nexus. According to creator FerretMyster, it's the "ultimate restoration mod" yet made for the game:
...with this initial release, have already covered 3x more than other mods with the same idea. There are still a few things I need to add to this mod, but those will come later through updates. I just wanted to share what I had been working on off and on since July 2017 to now.
Morrowind Uncut covers not just items and areas, but NPCs, dialogue and even diseases. Heck, there's even six new loading screens. Apparently to make it all work, Ferretmyster had to craft some "custom objects just to fill in some of the gaps", which is understandable.
[Nexus Mods, via DSO Gaming]