No, the source material is stored losslessly. Many different effects will be applied to the source material to make the moving images look the way the director wants them to look.
The creation of the original video is separate from the distribution of the video. In distribution the video will be encoded to many formats and many bitrates to support playback on as many devices at as many network speeds as possible.
The distributed video will never exactly match the original. There simply isn't the bandwidth. The goal of video encoding is always just to make it look good enough.
So? That fact only emphasizes the absurdity and loss potential here:
1. Acquire "clean" digital footage.
2. Add fake grain to said footage
3. Compress the grainy footage with lossy compression, wasting a bunch of the data on fake detail that you just added.
4. Analyze the footage to determine the character of the fake grain, calculate parameters to approximate it later with other fake grain
5. Strip out the fake grain, with potential for loss of some original image details
6. Re-add fake grain with the calculated parameters
If you don't see the absurdity there, I don't know what to tell you.