Not the type of secondary reference you're talking about, but YouTube temporarily banned Rebel Wisdom's Ivermectin Film that was a carefully balanced presentation of ideas from the leaders of both sides of the debate.

Here's their video about it: https://www.youtube.com/watch?v=x2MlXaRxlFo

"it is back up after appeal. It's great that it's been restored - though with no explanation of why it was taken down, or why they decided it was OK to go back up. Strictly speaking according to the YouTube guidelines they were within their rights to take it down, it says clearly "Categorical claims that Ivermectin is an effective treatment for COVID-19" are not allowed, and Tess Lawrie clearly made these."