Well, in an alternate timeline it did, apparently. I believe in Roxy: Wake Up we see Godtier Karkat and Dreamer Nepeta together in a dream bubble. So our ship did sail, if even for a few brief moments.
It’s kinda inconsistent. Like here Nepeta’s tongue is green.
Talksprites and other art from most of the walk-around flashs should not be considered canon since they were done by fan artists that were allowed to interpret the characters as they please.
I don’t think any classpect changes have ever been confirmed in canon; I’ve only ever seen conjecture, albeit popularized conjecture. But even Rose was never stated as undergoing any kind of role inversion, as far as I know.
