See the EDIT at the bottom of that page.
So while you have a good question, I think their current stance is not to worry about it. If you are updating or submitting a channel then they won't accept it if it's not scenegraph. Existing channels might still work. - It's a good choice though, otherwise January 1st the available channels could have been wiped out to 30 or 40 choices instead of over 500 available.