Normal render output is not square 1:1
Most of images/rendered are 4:3 aspect ration, not 1:1 square as you want it to be.
Highly doubt you going to get that feature.
In my case, i try to capture as much of a scene as i can, so wide aspect ration is a benefit to me. Hardly ever i see anybody need to have square image, unless you rendering boxes and weird objects tat fit into a box area.
How about vehicles ? Those all need wide angle view.
How about characters ? those all need narrow view images to show full height of the character.