It's worth noting that these were original videos uploaded to YT by the protestors themselves!
By your definition(s), YouTube can't possibly handle inflammatory leftist material.
If they don't remove it, they're clearly leftist biased.
If the do remove it, they're also clearly leftist biased, but for a different reason.
You can't have it both ways.
Removing things that make one side look bad - but not similarly doing the same for the other side - is bias, yes. Unless you think YouTube would have removed videos taken by the protesters if the situation was reversed, and it was a neo-Nazi protest that was looking horrible?
Or are you claiming that the people at Evergreen are all secret members of the Pepe Brotherhood and that they are not holding their leftist views honestly?
This was pretty clear in what DuskStar wrote. See the "the fact it was produced by leftists who need a far better grasp of optics" bit.