Sorry bullet, EsSentiallyMaYa was using that for NURBs, cause I wanted to show what the functionality of the preview was (i.e. going back and forth between different smooth preview states without actually changing the mesh).

So I don't think there is smooth mesh preview on 8.5, but it would still be a good idea to unbind the 3 hotkey, it won't do you any favours. Note that you can always set the divisions in the smooth history back to 0 if you have saved, but still have the history.