_,,,^..^,,,_ said:

For example, what if Disney in person had the chance to choose to release his animated features with or without grain?

That's quite easy to answer. Disney would have CHOSEN grain-free movies, but then he would have altered his animation process to account for it.

The fact is that cell animated features have been optimized during production to look appropriate on film stock. It's the same reason why sampling the colors on cells is the WRONG way for Disney to color time new digital releases.

I like grain, but to me adding grain to processed video is just as much a travesty as completely scrubbing existing grain. It's just artificial and the damage has already been done and you're obscuring more image detail.
If it's not there, it's not there.

Laserdiscs and most SD releases tend to be scrubbed to some degree to look good on home video.

In fact many companies used the same amount of scrubbing on their first HD releases (HD DVD and BD) as they used for DVD and those releases were dreadful.

It's an unfortunate fact of SD sources.