I'm a hotmail.com user and noticed this change occurred today (5/17). It makes zero sense to move the 'quick actions' to the far right of the screen, because now you have to look on the left side to view the sender/subject, then move your eyes all the way to the right, making sure not to move your mouse off that line, to see the quick actions. Then move your eyes all the way left again for the next message.
Because of the change in quick action location, it's actually faster to NOT use them and instead use the options along the top row for manipulating mail items.
I don't get why anyone even considered making this change in the first place, it makes zero sense. At the very lease give us the option to move it back to the original spot.