Morrowind remaster won't sell. It's one of those "hybrid" RPGs similar to KOTOR games - it has a gameplay elements of isometric RPGs: RNG combat, very few voiced dialogs - while looking like 3D action RPG. This just won't work for modern gamers. Its theoretical devs would need to either turn it into isometric CRPG or completely rework its gameplay to make modern action RPG out of it (as well as do it in the new engine to improve graphics and everything else). Both choices mean a complete remake, not remaster.

I don't know whether this leak means "true" remake of Oblivion, but that seems unlikely. Oblivion is relatively modern and you can definitely remaster it for new hardware without complete rebuilding.