I think that the largest issue I've seen from higher-resolution video formats isn't from the remaster as such, but rather that the flaws in the content that worked fine on lower-resolution displays become visible. A special effect or something that blended in wirh the rest of the video suddenly stands out.
For film grain, I'd personally rather not have it, but I use real-time filters that reduce it anyway in video that show a bunch of it, so it being there doesn't bother me that much unless it's exceptionally severe. A studio could probably do a better job with offline processing than my computer can in real-time, but...shrugs