I think they lied when they said that the blackout had not impacted the bottom line, it just makes sense to say that. Admitting that the blackout was working would mean you have to roll back the change and potentially hurts the IPO launch.
Even if it's true that the blackout was ineffective I think the real test for Reddit will be what happens July 1. I for one will not be using Reddit on mobile without RIF, it's what I've been using since 2012. I'll continue to use RIF as long as it's working and I'll also use Reddit on the desktop, but my mobile usage is about the plummet.
I think a lot of people are likely in the same boat, but even if they aren't it won't matter to me.