I know I represent a minority opinion, but I have never loved ACL(I liked it, but thought it was woefully overrated), and -- having seen the last revival --my earlier opinions were reinforced. The overrated show (IMO in the first place) did not age well.
Logically, the only way to revive ACL any time soon -- and not have it look like a tired relic -- will be to totally reimagine it. That said, when you think of a reimagining, you usually think about the physical production, the direction / choreography, maybe playing around with the book, maybe eliminating a song or adding some other song from the composer. The problem I have is that the score for ACL is its weakest component. How do you reimagine it, while retaining the original score? Also, some of the stories are pretty tired 50 years later...do you update some or all of the stories? do you get in a new composer to improve the score?
In 1975, I could just not comprehend how Chicago got lost in the ACL shuffle;I feel pretty confident that time has proven that Chicago is a more timeless show, with a far superior score; Of course, it won't have a 50 year revival, because it will probably still be running; if it has managed to close, perhaps there can be a 50th year revival of the current revival.