This is a complete joke even if the OP itself is horrible, but this has long term consequences in general
1. YouTubers themselves already have the ability to filter out comments that they deem inappropriate. With this new feature, they can now hide behind a wall when they fail to take accountability for the actions they committed. Example, if someone is accused of sexual harassment and such and they make a video denying these allegations, they can hide behind the like counter and disable the dislikes to not show the whole opinion. It's restricting public opinion on a certain matter to benefit the creator itself.
2. YouTube themselves has used this feature on their videos to censor dislikes. They censored the dislikes on their video discussing the feature to make it seem like this is a positive change as well.
What Grey is saying is a stretch, but the impact it could have can spill over to what he is referring to. This is a poor move on YouTube