Isn't there a lot more to this than she's saying?
As for giving away their rights, workshops were still fairly new and the concept of devising a script together in rehearsal, all still fairly new. Chorus Line, famously, but that was only a handful of years before. So, to expect them to have known better and not signed them away is both a bit insensitive but also not exactly fair.
But I think the dynamic with Bennett goes beyond that. A dresser once told me of the time Bennett restaged the top of Act 2, after the show had already opened, which of course almost never happen, and at great expense (but it was Bennett, so who would say no?). There was a huge fight with Sheryl Lee and Bennett was really nasty. So, that night, when that sequence was to debut, she called in. The understudy didn't know the new staging yet, and the production team had to scramble to put in the old costumes etc. She didn't show for a couple days, until Bennett sent her flowers and an apology.
Or there's the Phylicia Rashad's story of being the Deena alternate, but blocked from going on.
I think it's fair to say that was not a harmonious production, as that is always the director's job or responsibility.