You're referring to Apple providing AirPrint drivers for Canon printers. This wasn't the case for the Pro 9000 as Apple wasn't providing AirPrint drivers. It doesn't matter anymore because Apple is no longer providing printer drivers for the Pro 9000...
It looks like Apple and/or Canon fixed the problem. Apple no longer supplies the printer driver for the Pro 9000, but Canon's printer drivers on their website works properly now.
