From what I read there is no upscale in the MP because it runs the pair columns in frame 1 and the even columns in the frame 2... so after 2 frames you have the full 1920x1080 image.
It can be called Temporal 1920x1080p I guess.
Because that it generate a blurry effect between frames... I guessed it was because the FXAA but it is not.
PS. 3D uses this tech to render the things too... one frame renders a image and the second others to be combined to a full 3D image.
Edit - A shame from GG to use this weak tech to render the game in MP.







