It's true, Yao Ming had not signed a contract by the roster cut-off date, and therefore is not in the default rosters. He will of course be added through EA's official roster updates, and our NLSC roster updates.
When you use the roster update maybe. I believe it was an official statement from EA saying he wasn't in the game cause he hadn't signed a contract at the date EA finished the rosters?
Well, as far as I can see, he is in the game At least he is in the PC version, I think EA were talking about the console version where the rosters are from August 31st I believe.
Don't expect much from Yao Ming this year. Wait til he gets an Offseason with the Rockets training staff and a full offseason/training camp with the Rockets coaching staff. He is only 22, he will be a 16 point/10 rebouded/3-4 blocks player in the future.