It's interesting that no one has raised this question yet, even though the impetus for this thread was a suggestion from a cast member of one of the most dramatic revisals of a beloved, but problematic work.
Admittedly, revisals are, more often than not, problematic for entirely different reasons and rarely feel like clear-cut improvements over the original texts. Certainly, that was how I felt at Cinderella. But I found a lot of merit in both the sunnier new ending of the Applegate Sweet Charity and the more melancholy new ending of the Foster Sweet Charity. And though I definitely preferred the original Side Show. the revisal certainly had its acolytes.
In the right hands, I think a revisal of Mame could be the best way to salvage a show that so many cherish--and for good reason--but that many others also find objectionable...and for good reason.
Who would have the right hands? I can't tell you off the top of my head, but I'd be curious to know others' ideas.