That's a huge stretch to say anyone that watches or listens to pirated entertainment would never pay for it. I wish people that use pirated entertainment would just admit that they don't want to pay for it.
I don't really know anything about 8chan but my limited experience watching videos on YouTube leads me to believe that there are millions of people being radicalized through technology. Young, angry, possibly under-educated people can easily fall down into a rabbit hole of hate like never before.
It's definitely an issue worldwide regardless of race, religion or gender and unfortunately no one has the answer. I don't know if 8chan going down really helps stop radicalization but I don't think it hurts. I also don't think it's an affront to free speech if a hosting provider stops doing business with them. If the US government started arresting posters on 8chan that's most definitely a concern but losing your Cloudflare service or hosting is not breaking any first amendment rights.
Those 500,000 views wouldn't have had ads shown on them. Some solutions might be:
1. Being able to automatically unpublish the video if it's de-monitized.
2. Have a monitoring service available that can fight copyright claims in real-time.
3. Don't upload at night and then go to sleep. :)