He's been pottering away in abandonded Iacon for centuries, awaiting the day when some sucker would listen to his annoying war stories... While it isn't *really* Kup, it has his personality... and pretended to be the 'Last Autobot' so Benny would pay attention to him.
But now that we know that the Last Autobot exists, but it *isn't* this annoying box with a screen on it... well... that leaves something amiss...