"They fold when you land and replace the cape (if any) when equipped. They are styled as the cape + new Mojang cape:" was what Jeb said, so I expected that "styled as the cape" would apply to Minecon capes as well. If this is being worked on or Jeb never intended for it to apply to Minecon capes, then forgive me for reporting this.
The capes will do that next week: https://twitter.com/Dinnerbone/status/651771358423162882