Her cancelled date lines up with the Wicked 15th anniversary concert and she was a tour Elphaba so maybe she's involved. (Defying Gravity with a chorus of Elphies??)
I am on the side of keeping the casting within the broadway community. I think it's important for the integrity of the movie, and I think Schwartz is on that page as well, and I want to say that it will still be successful despite not using some Hollywood names.
I personally feel like the current tour Glinda and Elphaba, Ginna Claire Mason and Mary Kate Morrissey, are doing a splendid job and are the right age and have amazing chemistry.