I'm not sure that's accurate.
From the game manual:
To keep our community fresh and lively, the next best teams in your division will promote to fill in any Bot-controlled team spots in higher leagues. The league that a team will promote or demote to is random within the division that they are slated to go to.
That, is unclear. But I read it to be record, not winning conferences.
http://with-malice.com/ - The half-crazed ramblings of a Lakers fanatic in Japan