1. Definition of what is a conspiracy and what is not. There are some hot topics out there all the time (e.g. Trump and Russia collusion) - pointing out and not pointing out "conspiracies" is a statement within itself. You only have to think about Twitter and it's "verified accounts" hot water not so long ago [1].
2. Adding fuel to the fire - for some conspiracies the idea of covering them up makes them more real for many people. There are many posts on various social media platforms with the tag line "share this before <X> takes it down" (e.g. Facebook videos [2]).
3. Videos that debunk theories could also get thrown into this automated mess they'll undoubtedly make and will probably incur demonetization. The result of that may be less debunking videos, actually poisoning the well further.
4. Generally squashing freedom of speech means that needed discussion on a particular topic can't happen.
What I think they should do:
1. Have this as an opt-out feature which is mostly hidden, or an opt-in feature which is obvious.
2. Pick controversial topics of any kind and find for and against cases for them, allowing the user to investigate them both. Picking a side is dangerous.
3. Have smart humans go through and carefully select for and against cases - don't try to automate this as it will be gamed.
4. Don't use this information for classifying whether videos should be monetized.
[1] https://www.businessinsider.com.au/twitter-clamps-down-on-ve...
[2] https://www.facebook.com/TaxationIsTheft2/videos/51317619238...