Wiktionary
on the cutting room floor
a. (context idiomatic English) Not included in the finalized version of something; deliberately rejected or unintentionally overlooked.
Usage examples of "on the cutting room floor".
As one of the critics said, we must have left the good stuff on the cutting room floor.
Some of what was left on the cutting room floor when I turned in the truncated version deserved to be left there, and there it remains.