Copy and paste have nothing to do with this.
Cut and paste has nothing to do with it either.
However, cut and then don’t paste, but cut something else, and it stays in a list. Cut more and it’s added unless it’s pasted before the next cut or copy.
The thought behind it is that with a copy you still have ‘the original’ in the document and with cut and paste it’s safely placed in a new location. If you cut, and then copy or cut again however, you have lost your data. This downside with cuttings became this new feaure which has the benefit of allowing the user to cut and cut and cut and it all gets added to a list and the user can then, whenever, cmd-shift-v see this list and tap on whatever to paste.
So, should we call this feature Clippings or Cuttings?