They would need to put much more effort into these zones than into the cata revamp, because I think these zones are overall pretty shallow, story- and questwise as well as the overall atmosphere, layout and depth. I think if they would revisit them, they would need to create them new and not just flatten out the questlines to please the nowadays standard, but there is no reason to do so, no cataclysm.
They would need too much resources for no topicality, which will result in a much bigger rage than they had in cataclysm. Leave that godforsaken place behind. Just leave it behind.
After leveling so many alts, honestly i'd just prefer they find a way to phase outland totally out of the leveling experience entirely lol.
Seriously. It's one of those expansions that if you didn't play it you really don't care about it. Only good thing was Sunwell, and only because that raid is still difficult to this day (other older raids even a Holy paladin can solo at least part of it).