YouTube seems more interested these days in telling you what to watch, then letting its user express any opinion, wouldn’t be surprised if comments were hidden next from everybody.
The dislikes were hidden specifically to protect the images of brands. Think of things like game trailers or movie trailers that would get overloaded with dislikes if people perceived them as bad. I don’t think Disney really pays attention to their dislikes. They and other companies prefer them to be hidden however, so that when Nintnedo pulls another super Mario Wonder for $70 that the haters feel alone about it.