I was with you until your last 2 sentences, the fact that it is going to be a film, and all that that entails, is what interests me the most(non sexy cat-wise). Reworking the form to fit the different medium is just what
Cats needs, it exists and will continue to exist until the heat death of the universe on the stage, but this is a chance for it to be something else as well.
Take Powell and Pressburger's
T, an opera taken off the stage and turned into a wonderful and beautiful film, one that takes advantage of everything film offers(editing, special effects, camera angles, camera movement, the camera dictating what you see, the whole shebang) to create a masterpiece of its own.
Here is a great interview with George Romero talking about the film -
https://www.youtube.com/watch?v=c3Wo8ICLlIQ
Now the odds of this being anywhere as good as that are slim(Hooper and co. are no P&P), but the chance is there for this to be its own wonderful thing and not just a camera shooting the stage show.