If you didn't see it, Shonda Rhimes' Shondaland website did an oral history of the making of it for the 20th anniversary in 2017, with interviews with most of the people involved. It does cover the unreleased soundtrack.
https://www.shondaland.com/inspire/a13138172/brandy-whitney-houston-oral-history-cinderella/
A Never-Released Soundtrack
Norwood and Houston were both at the height of their careers, and releasing an album featuring the two of them just seemed to make sense. But the "Cinderella" soundtrack was never released, and 20 years later, it’s still never seen the light of day.
Neil Meron: We all wanted to release an album. There is an album just about done and ready.
Paolo Montalban: Ah, the elusive soundtrack. The thing is gorgeous. I’ve heard it.
Craig Zadan: About a year before Whitney passed, I visited her in Atlanta. She confided in me that her favorite project in her career was "Cinderella," and that the heartbreak of her career was "Cinderella." It didn’t make sense to her that there was no album, she just couldn’t understand.
Neil Meron: There was a pissing match between Brandy’s label, Atlantic, and Whitney’s label, Arista.
Debra Martin Chase: It was Atlantic that didn’t want to do it. Clive Davis at Arista was like, "We should do it just because it’s so great. It just deserves to be released." He really tried to convince Atlantic, but Atlantic thought that it would hurt Brandy’s recording career. Because it was so poppy and mainstream, and they were really focused on selling her as an Urban artist.
Craig Zadan: We were so naive in the beginning, we thought it would work itself out. We couldn’t believe they dug their heels in like that.
Neil Meron: The two labels were never able to come to terms.
Craig Zadan: Whitney knew how important it was to everyone, and to her, especially. She was so proud of it. But no one would compromise, they were willing to stop an album from coming out just because they were playing this game of chicken with one another. It was tragic.
Neil Meron: Ted Chapin from Rodgers and Hammerstein Organization called me last week and he’s been talking to people about trying to get the album out, finally. It would have to be looked at to be remixed and mastered for 2017, but it’s basically done.
