journalofavegan yes, it is definitely possible. when you start a discussion content is the first post and we can easily allow the first post as empty and we can also disable the content block area or we can make title content as first post content but there is a limit to the discussion title length. with help of an extension, someone can make it work.
these days in terms of SEO, I have fallen in love with quora. Their way of handling everything is so beautiful, few features like displaying similar answers from different discussions (related answers), related discussions: internal linking between pages (we have this feature as an extension), schema and a lot more.
