Earlier quoted context omitted.
I think they're overstating how many casinos use RFID. The last time I looked into it, only the Wynn did - and then only to track denomination, not as a unique identifier. (Perhaps someone can correct me if things have changed) The goal is to help security detect cheating by tracking bets at the table games electronically, not prevent counterfeiting or theft.
Most RFID tags have a unique identifier in them. You can duplicate said identifiers, but if they are indeed globally unique and can not be reprogrammed then the thief is still out all that money and the chips are worthless.
So 32bit global ID for all chips would take a long time to read, possibly minutes if it's a table with 1000 chips on it. A 4bit code that just ID'ed value and allowed you to spot if somebody had 'mistakenly' mixed up some low value chips in a stack would be much quicker.