OK. there are 2 moveTo plugins - one is called moveTo and the other one is call Platform MoveTo. it is still not clear which one he is using in the tutorial but the second one does have the on Hit Target Position because the other things that are used belong to the first one. So this is very confusing.
I rename "On hit target position" to "Condition:On reach target position", the behavior are equal. Sorry for confusing, I will change it back.
rex_moveTo vs rex_platform_moveTo rex_moveTo will move sprite straightforward. rex_platform_moveTo drives a sprite which has official platformer behavior to "move left" or "move right", i.e. it is an addon of official platformer behavior.