They already do that, sort of. The last I heard, people watching with an ad-blocker also blocked the mechanism that incremented the watch counter. This may or may not have been deliberate. The interesting thing is that the video appears in people's Watch History ad-blocker or not, so there was always an easy fix sitting in plain sight.

They told creators about the watch count problem along with at least one other secret thing that they said they weren't allowed to talk about. Charlie / Cr1TiKaL / penguinz0 said as much as he could about it a few months back.

I think the secret thing was probably "we're working on a way to get those view counts back, but don't tell anyone because we want to discourage people from using ad-blockers and if you tell them they're costing people views, it might convince them to turn it off."

Assuming true, that's all now out of the window because they've "fixed" the problem.

I expect another fierce attack on ad-blockers in Q4.