I don't think any faction in the Warcraft universe has ever demanded reparations from another. And I don't think Night Elves want any orcs helping them rebuild. More than likely the Night Elves just wants the Horde to fuck off and never see have to see their tusked green faces again.
If the Alliance was allowed by the writers to dictate terms, then realistically
this is what should happen. Dismantlement of the Horde war machine by smashing their industry, keeping them from massing armies, deporting the tribes that are too warlike, and a deprogramming period for the rest, and then after like 20-30 years the Alliance withdraws, having safely pacified their former enemies. Basically what the Allies did at the end of WW2.