We're still waiting for actual figures, the 7% often cited was from weeks before the protest. Reddit Inc's behavior was extremely unprofessional, they did an absolutely terrible job at controlling their community, and the quality content that's the main driver for Reddit's success has took a massive hit as they alienated their core niche. They will undoubtedly vilify said core niche in their communications, in an attempt to fool prospective investors into thinking they just "got rid of a bunch of nerds who were against their totally sane monetization practices", but what they really did is they cut off the 1 from the 1-9-90 rule, they drove away their core contributors who kept the other 9% of users engaged and the remaining 90% lurking and still consuming ads.
The real impact to Reddit's platform isn't going to happen today or tomorrow, the damage will take months to set in as the reduced value of content results in reduced user engagement and retention. And by the time they see the charts, it will be too late to act. As for their valuation, it is up in the air due to the delayed effect, but any smart investor should see the clear signs shown here and exercise extreme caution about the valuation they assign to Reddit. The site appears to perform better for now, because it's easy to force dissenting voices off the platform, reign in unruly mod teams and force them to open up their communities to their specifications, but pulling the lost users back on the platform, especially their most valuable and connected contributors whose trust and buy-in is now thoroughly broken, is not something Reddit can force. And it's crystal clear that Reddit can no longer accomplish anything regarding its community without use of force. They lost the carrot and only have a stick now, and sticks don't bring value to your platform.