While demonetization of videos have been happening for a while when it comes to Youtube they have made some recent changes to their policies that happen to be vague enough in description where pretty much anything remotely news related could be considered "Not advertiser friendly". There is no information available at this time to conclude that advertisers have contacted Youtube in regards to specific channels to say that they do not want their advertisements showing up on specific channels one way or the other. Only that Youtube itself has deemed specific content being not advertiser friendly.
Here are some of their vague policies.
Now there will be people who are quick to say that it is their site, they can do what they want in regards to what they will or will not allow their users to do or make money on. While this is true it is also important to note that Youtube essentially has a monopoly on user created content that is unmatched anywhere else, and with presidential elections coming right around the corner in the US, having the ability to shut down channels monetization that Youtube deem offensive with vague rules such as these allows Youtube political control if it chooses over a candidate of their choice. This would not be limited to simply presidential elections either. Everything that requires a vote in the US can be controlled like this by Youtube at their discretion. On top of that, there is no sign of consistency in any of this and seems to be targeting videos almost at random and people are not being made aware of this until sometimes long after monetization has been taken down. When "controversial" can literally mean anything, Youtube has essentially censored every single one of its users at its own discrepancy without giving any of its users a clue as to what they can do to avoid it.
Already this is harming large channels including one such individual Phillip DeFranco who is apparently getting his monetization shut down entirely. As he points out in his video, Youtube's standards make it nearly impossible for anyone to cover news as all news could be considered controversial under what appears to be very selective targeting on Youtube's part. This video has already been viewed almost 2 million times and has over 150k likes in 24 hours. You can watch his full thoughts on the matter below.
Phillip DeFranco updated people on the situation while this was being written. While the situation is no less confusing it does offer more clarity on the whole ordeal.
While it is true that Youtubers can continue to make their videos and not get financial compensation through advertising, many of the individuals being targetted have put a great deal of work into editing and delivering quality content. If Youtube continues doing things like this, it will diminish the quality of entertainment Youtube can deliver to viewers and will likely give incentive to existing Youtube personalities to seek a platform elsewhere.