I've been making many SEO changes to my site in the last few days, and several hours ago I noticed my best page is completely gone from Google's index. I checked for it with a site: search and conventional searches. The page has been online for almost 10 years, and has been #2 for its target phrase for as long as I can remember. I've never done anything even remotely "black hat".
Should I be rolling back changes right now, or could this be a temporary thing? If it could be temporary, how long should I wait before rolling back?