Revisited is not a Remake, it's a reimagination of Morenatsu.
Essentially the Original is unfinished, and full of social problems, such as having underage characters, rape, kidnapping, grooming and other aspects that are not cool. Those were completely removed from Revisited, all characters are +18 and the main protagonist now can be a Human or a White Fox, all characters are re-drawn and all routes will be different and finished. Some routes haven't changed a lot, but some of them are being completely rewritten. So yeah, that's the difference.
If you wanna see NSFW scenes, only the Original MOrenatsu have them, Revisited will focus first on finish all routes, THEN, they'll make the NSFW scenes, those are expensive or costly to make.