Reddit will continue to highlight Weekly/Monthly Average Users to the press and advertisers, since those metrics won’t take much of a hit. You visit the site once to vote in a poll in favor of continuing the blackouts, you’ll get counted in those.
Those more granular metrics like session length and especially Total Posts Viewed are what really matter when you’re trying to run ads, and it’s hard to imagine a world in which those did not take a huge hit when most of the major subreddits are either blacked out, or (even better) flooding the front page with repetitive pictures of John Oliver.
Advertisers only care about the conversion of engagement to actual purchases.
They already said that with the blackout they couldn’t push specific advertisement into specific subs.
Just highlighting weekly/monthly users is not gonna work in the long run.
If those only engage to what is up on the front page or engage for just a second of 5 then it defeats the point of targeted ads.