The point is that its not a search engines job to make that determination. People will decide for themselves and whatever the algorithm is, it should seek to remove the personal biases of the implementers and be blind. It should seek to serve the asker not change the asker.
I feel like there could be a term, similar to "uncanny valley" where instead of detecting the in-human traits of something attempting to appear human we see bias in something attempting to be unbiased.
They fairly pointed out the evidence of mainstream news sources promulgating conspiracy theories.
It is useful to make a distinction between news organizations and non-news organizations but it is not useful to apply any sort of value judgement of either based on that fact alone.