This plate, for the MK3S, moves the front fan up 8mm and right 5mm to provide a better view of the nozzle. There should be just enough slack in the wiring to move this amount.
The fan ductwork has been removed. The side fan works just fine with 3 screws holding it in place. I have printed PLA, PET, Bridge nylon and  Prusa PC Blend with the ductwork off for several months with no ill effects. 
The new position allows easy access to the nozzle with a wire cleaning brush and you can easily see first layer adhesion without standing on your head. 
The small hole indicates the upper left side of the bracket. Older version is pictured in white. Update: Some parts made with high temp materials (ABS, PC Blend) need the fan and shroud in place.