the grain matches perfectly on the new elements. You are watching a highly compressed video and grain gets eliminated/blurred. you can clearly see the grain is there if you watch it in its 720p res, plus if there wasn't heavy grain on the background there wouldn't be the amount of moving video artefacts on the background. It would be almost still as there would be no movement.

And adding movement to the face was tried but it looked fake. It may work on an alien but on a human face it becomes noticeable due to the way we recognise real life objects. Besides, there is zero facial or eye movement in the 2004 version so i really don't see what the problem is here.