That means that there's a critical mass of people using ad-blocking to trigger YouTube into fighting them.
Ergo, there are a lot of people unhappy with watching ads on YouTube. Honestly, when I watch YouTube without an ad blocker, the experience is horrible.
Ergo, when (and if) YouTube somehow wins that fight, a large number of people will be generally unhappy with YouTube. A certain percentage of them will quit YouTube.
Apparently the math works out (or at least YouTube think that the math works out) that the number of people quitting YouTube will be lower than the number of people who keep watching ads.
I hope they're wrong.