I've never heard or seen that. Seems weird as well. Source?

they are probably talking about their caching. Videos with low views are not cached at all servers, especially not higher definitions. So you want to watch the video, the server realizes "oh hang on, I threw this one out, let me grab it again from another server". while the server fetches the fullHD video, you get it in 360p

I recently had a video with very low views that just wouldn't load for minutes on end. Was wondering if they were down, or if it had to be grabbed from some tape archive because a disk crashed. After about 10-15 minutes, it slowly loaded. This was at all qualities, browsers, and even when trying from another continent.

Is that true? Do you have a source on that?

Maybe I'm an isolated case, but many of my videos from 5 years ago with few views.

They were filmed on a Nikon DSLR in 1080p. A few weeks after uploading they were fine, 1080p. Several months later, I noticed a few were 720p, and now many are 480p, but a extremely poor quality 480p that looks more like < 240. For a few that are still 720p, and some that are 480p, the framerate has been reduced to maybe 4 fps.

Maybe it was the codec Nikon was using, but regardless, they're basically gone, and I no longer consider Youtube a "safe" place for videos.

I would send links, but I don't want to dox myself.