I know this was an old topic, but I never had someone from Deepbot either shoot down or identify that this would be put in the process of being a feature. Someone from Deepbot has responded to someone else's comment (which wasn't the original post), but not the original topic post. Perhaps the original post was confusing on exactly what I meant.
Let's say a user does "!requestsong blah", but when Deepbot outputs the song that was added, it was not the correct song due to the way YouTube picked the song. It would be nice for that specific user who requested the song to be able to type "!wrongsong" and it will remove the last song that that specific user requested, even if another song request was already made. Moobot has this feature in case anyone is wondering where I go this from. A lot of people hate requesting songs once they find out I am using deepbot because they don't want to ask a mod or the broadcaster to remove the song and they can't go get the YouTube ID easily on a mobile device. In case it makes it less confusing of what the actual request is, Moobot's definition of the command is "Removes your last requested song."