Hello,
This is not an exact issue, it is more like a feedback suggestion. Now since I've played ArmA since the first one (formerly known as Operation Flashpoint) I am more or less used to the mission editor zooming being reversed, when you move the mouse scroller forward or backward.
My suggestion is that there should be an option somewhere so you can toggle between the old style and the new "normal" zoom as used in ArmA 3. It has always been like this since back then.
Furtheremore if possible I would like if the "classic" layout style of the editor was even more like the old one, at least it has been the same all the way since the first ArmA (OFP), the UI being to the right, nothing by the top or the left side.
Sorry if I am a little old fashioned, but it would be nice, and at least you can toggle between the settings, so you can get the old as well as the new.