Got a news site with a forum and on the forum we just now realized in Q1 all of our external links that people post (tens of thousands of these as forum as over ten million posts) went from nofollow to not having any markup so they were telling google to follow them by a script error.
We then were hit by Google May update. Could these things be related?
Regardless, should we just overnight go back to nofollow? Is there anyway to tell google about our mistake? I don’t want them to think we are playing weird games.
I doubt that the links going from nofollow to follow impacted your rankings, unless most of the outbound links are absolute trash and Google decided the site looks like a link farm.
Depending on what kind of safeguards you have in place, the size of the forum, and the size of your moderator team, I would consider going back to nofollow though. Offering follow links on a forum is a great way to attract a ton of spammers.