I recently asked the merchandise hostess aboard the Wonder, and she said, no there is no soundtrack for sale.
She did comment that many people ask.
My friends and I discovered that at least two different soundtracks seem to be running at the same time.
We were waiting for an elevator, listening to one piece of music, and as we boarded the elevator, it was playing a different piece.
My personal guess, at least for the Wonder, is that many pieces played are from motion picture soundtracks, and not all of them are Disney.
I imagine it would be impractical to try and wrangle all the rights for these various non-disney pieces.