hmm. meanwhile, there are like hundreds of vegan video blogs on youtube right now. Some have been there for years. So the youtube corp must be really really bad about vegan censorship.
I did read something about them censoring violence, blood, and gore. Maybe they just don't want us to post videos of slaughterhouses.
You seem to mistake quantity for quality. I don't think vegan youtube is particularly targeted (although some vegan content has been - vegan gains has complained about it, from memory he even got his channel taken down for a while). When I type "vegan" into youtube's search engine (as having cleared my internet history, so no cookies/history), I get a mishmash of both commercial and non-commercial content. Some of it's legit, and some of it's just there because youtube promotes the channel.
Type "news" (again having history cleared). You'll get news from your locale, and it's all likely to be from corporate sources. I get Australia corporate news first, then the big US news giants (NBC, ABC, CNN) and also UK (BBC,BBC3 etc). These are also the sources one will get when any sensational event (like a terrorist attack) happens. Independent sources (especially those that question official narratives) are often stifled, first in search results and often by outright censorship. This is what happened to a video I made some years back. It went viral then was quickly age restricted then eventually deleted.
Certain subjects also yield primarily corporate owned/corporate backed results, and there are many many examples of youtubers who have complained/left because of the stifling of their content on spurious (often hypocritical as BitSizeVegans' video shows) reasons. Youtube favors corporations and corporate backed entities now, both on their home page, what comes up on search results, and what gets censored. Most youtubers joined youtube because it was an independent platform for individuals to upload their videos with a chance to get seen/noticed/have their message spread (whatever it is). If that's on a subject like motorcycle racing, youtube doesn't care, if it's on more sensitive subjects, censorship is often implemented. Not always, but frequently.