The only reason traffic went down is because of mods locking/limiting their subreddits. They do not speak for the community at large and if they were indeed removed, traffic would be instantly back to normal. No need to employ conspiracy theories.
I may agree with the reasons for the protest, but I disagree that mods have the right to kill the whole community. /r/firefox for example now only allows images of red pandas. They killed the subreddit just to funnel users to their lemmy instance.