If the system can't boot into 9 because of the firmware, then they are not capable of booting into 9, period. Classic is going to remain an option for older software, but an actual bootup into OS 9 cannot be done. Previous eMacs will boot into 9, present models will not, but have Classic mode available (not a 'downgraded OS 9' AFAIK, all the software pieces are there, but the hardware won't allow boot to 9)
Where have you folks been the last few months while Apple continues to announce 'Won't boot to OS 9, but you can continue to use your older software in the Classic environment' yes, even the eMac is listed with the same words "Need to use your Mac OS 9 software as well? The eMac lets you do that, too, running all your Mac OS 9 applications in Mac OS X Classic mode." straight from the Apple eMac tech specs page.
It's a firmware change, believe it.