This result honestly sounds like their best-case outcome. I don't like much of what Google does, but I'm certain a lot of discussion went into what would be viewed as a "win" on this call, and my guess is "some number of people stop using ad-blocking software" actually beats out "some people are converted to subscribers" (an effect not measured here and somewhat necessary to get any context for one data point) by virtue of Google being an advertising company.

Regardless, they're targeting only low-hanging fruit: people who use ad blockers to block ads. Sounds tautological, but this excludes anyone concerned about privacy. Nobody using an ad blocker in concert with other add-ons is going to be converted here. And I sort of wonder whether media coverage from when the crackdown started inflated ad-block installs among people who'd never used one, thus making this win less substantial on a longer timeline.