The real data point will come in a few months/years. On every social media platform, a small percentage of users drive the majority of content. On Twitter, for example, 25% of the users create 75% of the tweets. So estimating the effect of Redditgate by traffic is a poor metric (at best a trailing metric). Lots of lurkers (which is the vast majority of users) will still drive traffic until the content becomes worse. And for the many users and moderators of Reddit which were creating and curating nearly all the content, I’ve got to believe a significant percentage are irretrievably angered by their FREE efforts being dismissed by u/spez and have left. Just losing the efforts of the bot subreddit over the next few months will flood Reddit with exponentially increasing shitposts.
I think many are coming to Lemmy just based upon my anecdotal observation that the quality of posts on Lemmy has increased dramatically in the last 3 weeks.
More importantly, traffic is a trailing indicator. The protests and anger were from content creators and moderators. As they leave, the quality on Reddit will decrease significantly but that will take months/years. And the traffic will decrease but will follow the drop in quality content and moderation. Based upon the increased quality of posts on lemmy just in the last 3 weeks, many of the content creators have moved to the fediverse.