My bet is that people will start posting a comment saying "upvote this comment if you want to downvote", the comment will rank first and it will be as if you have a public dislike count
The tiktok community has adopted a similar strategy for voting on comments. Someone will post a spicy comment, which gets a certain number of likes, then someone will reply with the comment "L" (as in "take the L, you lose"), which competes for likes.
they might, but chances are that if you force people to move their dislikes into the comments, they're going to provide more information than just "downvote", and the top comment will be some variaton of
* "the information in this video is wrong"
* "i don't like the person who made this video"
* "this isn't the content i expect from this channel"
all of which is vastly more useful than just a downvote.
I doubt YouTube’s comment ranking would put this at the top, since it looks a lot like the type of brigading that they are trying to reduce with this change.