Generally I think the most we’ll get is the arc wrapping up in Shadowlands and then it getting swept under the rug. Sylvanas will have an ending ambiguous enough that people can debate about her forever, Tyrande will die and be replaced by Shandris, or go back to normal, and the night elves will go back to that odd limbo of just being tall wood elves, and things will move on.
In terms of Forsaken, lands lost doesn’t factor because they did push the Alliance completely out of Tirisfal, having only lost Undercity and Brill. They can return at any time, just, much like the night elf refugees still around Stormwind, Blizzard does big things then drags their feet actually showing any payoff.
I’m personally of the belief that Teldrassil shouldn’t be regrown at all, and instead the night elf lands that are currently neutral should become theirs. Hyjal, at the very least, and then Felwood and Ashenvale fully restored. The night elves have had a narrative of ‘oh our lands or damaged or dying woe is us’ for 16 years now, maybe it’s time to show what killing all those corrupted bears and satyr actually did for cleansing Felwood.
Forsaken it’s a bit tougher, but it has been since Cataclysm. Their entire narrative goal was to get revenge on Arthas, which they did, and then they became tools of the faction war narrative not once, but twice, making it almost impossible to discern what their goals or themes are now. Pulling them back to Wrath era themes, at least in tone and aesthetic, would be a start, as well as making their Grand Executor leader, which is canonically the line of succession, none of this Desolate Council stuff… Brill can be rebuilt and Undercity can be cleansed by whatever Blight cure they have. And we know they have it… failing that, the recent Eastern Kingdoms guide suggests that the Blight around the Undercity is dissipating.
Ideally, a timeskip would be a good idea to cement all this, though the length is up in the air.