One reason to abort/cancel the save would be to save time. Sometimes I end up spending a couple/few hours on a server doing mindless prep for an LP episode, it can take a very long time for that replay file to save when I leave the server. If I could just cancel the save, not only would I not have to remember to delete the replay, I also wouldn't have to wait for it to save, just to end up deleting it. That would also save my HDD from wasting effort on the save/delete process.