Mike,
No, there is no requirement in the C&BLs for a banquet, but there is a requirement for an awards ceremony.
At almost every venue, if you have a banquet, you get the room for free. The venue makes their money on the food and beverages.
If you don't have a banquet, you have to hire a room for $12,000 to $15,000 if memory serves. That would add around $15 to every registration, assuming 1,000 registrants. West coast conventions are usually a little smaller, so the price per person could go up more. It doesn't appear the folks who are willing to pay for the banquet mind that they are subsidizing the awards ceremony. When my job permitted me to go to the Nats, I always attended the banquet and considered it money well spent for an enjoyable evening.
I would suspect that moving the awards to a different room from the banquet negates the advantage of having a banquet, as the awards ceremony room would be an additional charge.
Regards,
Bruce