Simply judging on the preview video for the show on the website, I feel that this harkens back to the mega musicals of the 80's. I'm not saying that that is a bad thing, but that isn't something that audiences seem to go for these days. That is of course, if it is something like Phantom or Les Miserables, but that is a whole different ball of wax.
Look at recent 80's style mega musicals such as Pirate Queen and Tale of Two Cities. Both of those shows were ones that found a rather limited audience and closed rather quickly. Not that I wish Rebecca ill will (in fact I am kind of looking forward to seeing it because I like that style of show.) But, I am not sure I see this lasting long once it opens. Specially since it is opening in the fall. It may have had more staying power if they opened it up in the spring. But, I have the feeling not by much.
"If you try to shag my husband while I am still alive, I will shove the art of motorcycle maintenance up your rancid little Cu**. That's a good dear"
Tom Stoppard's Rock N Roll