It would appear that YouTube really doesn't like hosting popular videos unless they get some ad revenue off of it. This would explain the #blender situation as well as their changing of ad sharing requirements.
"You must be this popular to get ad revenue, but not too popular without ad revenue".
I think we figured out their sweet spot for how they monetize the service.
Blender, YouTube, Monetization musings Show more
@whjms That's my suspicion as well. As to whether it's automated or not that's an interesting question. My suspicion is the flag was set automatically, though I'm thinking a human is shepherding the process.