Apparently they are using some new algorithm that is doing this for many types of videos including ones on video games so it doesn't appear to be only targeted towards conservatives.
Ah...that makes sense. I was watching one Youtuber yesterday and she has over a million subscribers and when she did her "subscribe to may channel and hit the button for notifications" thing she mentioned something had happened recently where many of her subscribers are no longer getting notifications. It appears as if they are changing things around and some have taken it as if it was a slight towards them. (and this is a makeup artist, so odds are... not conservative )
Also, YouTube is a private company and therefore has the right to ban, censor, or demonitize any video they like. I'm sure their agreements are 100% in their favor (as they should be...I'd do the same) so any legal fights will probably not be effective.
I figured as much myself.
Having said all that, just as they have the right to manage videos on their site, we all have the right to boycott them (
except especially for the cat videos, of course).