Yes, they change it back in a hot fix due to people being unhappy with the change.

The problem is, some people want "when mouse over nothing, do nothing" and other want "when mouse over nothing, cast on me"

My opinion : when there's diverging opinon for one thing => make an option for the user to choose...

In fact, when the dev team need to choose between multiple thing to do, it should always be an option in a menu (color of AoE ^^) unless it is a memory or resource problem or too different to be a trivial implementation.

PS: It's usually a trivial implementation and it's the way I do it for all the IHM I developped : choose a default option, let the user change it if he wants it.