The plot thickens...
It seems Google may have taken down Blender's videos on YouTube because they wouldn't display ads for them.
https://www.blender.org/media-exposure/youtube-blocks-blender-videos-worldwide/
This was after initially telling Blender it was just a "known issue" that their engineers were working on.
It's such a weird way of going about it though. If they are going to force YT members to show adverts, why not just say so openly?
And why take the videos of a major partner down without explanation for 4 days, lie about it, then spring the compulsory ads on them?
Something odd going on behind the scenes.