Not all true mate... some stations have an ABT printer located at the gates. Example is here at CLE. We ask for some passengers to volunteer bags and we print out system generated tags on a printer located at our main podium. This is of course for our full mainline flight for ORD but we are allowed to print out tags for the express flights as well if a passenger so wishes to choose to send their carry on bag to their final destination baggage claim instead of having to wait for it planeside at a connecting point. Just have to ask a gate agent and see if they can and if they have the printer located at the gate. Makes it a bit easier sometimes rather than holding boarding up to write out a tag and try to figure out the correct connection flight. We started doing that here maybe two or three months ago during the final stretch of summer loads.

Cheers
-CLE-