I’ve been playing with WordPress optimizations recently and I found one great plugin wp-author-date-and-meta-remover. Mirror of wp date and meta remover is here – http://www.pc-freak.net/files/wordpress-plugins/wp-author-date-and-meta-remover.zip
The plugin wipes out any Author info left from the multiple loaded plugins or unnecessery meta data. For latest version check out – https://wordpress.org/plugins/wp-author-date-and-meta-remover/