I'm sure that directors who think they can get away with it will try to put things from the new film into the stage script. That said, MTI will surely say no to anyone who does the right thing and asks first.
I was a young and callow music director back in the late 80's when I did a small-scale summerstock WSS, where the director indeed replaced a major portion of the show's book with that of the '61 film. (This included changes to "America" and making "Somewhere" a duet for Tony and Maria, etc). I hated it. Hated it. But at the time, I didn't really know I had options to call her out on it, and I did want/need the job. If I were to face the same kind of thing nowadays, I'd be on the phone to MTI in a millisecond. |