After what felt like half a year the free default WordPress theme Twenty Seventeen has finally been released on WordPress.com over Four (4) months late, which as far as I know is the longest that it has ever taken for a default WordPress theme to be released on WordPress.com after it had already been released on WordPress.org, but I could be wrong.
The Twenty Seventeen theme is probably the first free WordPress.com theme to ever have a video header option.
John Jr's Blog 