I also hope for the second option, because it seems unlikely that Google would intentionally whack major websites with no guideline "issues".
Why does that seem unlikely. For as long as I've watched Google going back 10 years now, every single change produces results that whack websites for no reason. For what ever reason, those sites are not looked at favorably by the new factors that are currently at play.
Sometimes, more get wacked than other changes and this looks like one of those times.