Without knowing anything about the original SHUFFLE ALONG or this new production, only going by what's written, I can see how they might actually succeed in getting to be a Revival.
As Mr. Nowack points out, a new book is usually allowed for a Revival. Significant alterations to CABARET, YOU'RE A GOOD MAN CHARLIE BROWN and PORGY AND BESS (among others) didn't stop them. CANDIDE and ANYTHING GOES, shows that have had multiple different iterations, also have been nominated as Revivals.
However, those also maintained a fidelity to being identified as the same show, just with alterations. ONE MAN TWO GUV'NORS petitioned and failed to be a Revival, which was much more questionable since the material was all-new and only based on THE SERVANT OF TWO MASTERS.
The thing that seems in debate here is how much of this is the original material of SHUFFLE ALONG, and how much of is the story of the original production. The title and original description surely seemed to indicate something new. But what if the majority of the text is the original material? Is there anything in the bylaws akin to the Original Score rule about 51% of the content must be original to qualify?
Words don't deserve that kind of malarkey. They're innocent, neutral, precise, standing for this, describing that, meaning the other, so if you look after them you can build bridges across incomprehension and chaos. But when they get their corners knocked off, they're no good anymore…I don't think writers are sacred, but words are. They deserve respect. If you get the right ones in the right order, you can nudge the world a little.