New additions are focused on popular and trending sites. If you know of a particularly popular site whose content can be embedded, you can inquire about it in the discussion thread. Don't forget to include an example of a URL whose content can be embedded. Alternatively, you may
start a conversation with me if you want to sponsor the addition of a site. Otherwise, you can always create new media sites for yourself using XenForo's
BB code media site manager. This is a default XenForo feature that requires no add-on.