Obviously they thought they can, why else the horrible sharpening filter in the upscaler to fake more detail. MS gambled that most games wouldn't reach 1080p and that they would have the image advantage side by side with contrast boost, gamma adjustment and artificial sharpening in their upscaler.
Seems people could clearly tell the fake 1080p from actual 1080p and MS had to remove the sharpening filter after facing backlash.







