The tune of "You Say You Care" was retained in the film as background dance music.
I don't think one can really compare the film to the show - like apples to oranges. I think that if the film had kept to the "Roaring 20's" era, it would not have aged as well as it has.
And what ever became of Yvonne Adair, who played Dorothy Shaw on stage? Both she and Miss Channing came to prominence in the revue "Lend An Ear." She handled the ballads in "GPB" beautifully. But then she seems to have faded from view.