Originally Posted by Often1

She was mistaken. There is no limitation on champagne as opposed to any other form of alcohol.

However, alcohol served in international airspace, e.g. after airborne for purposes of commercial aviation, is served from "bonded" stock (think of it as duty-free). What is served pre-departure is subject to duty and local, e.g. Iliinois taxes. Thus, a carrier must keep a separate supply which is not bonded or pay duty and taxes on all alcohol on the aircraft.

Space is limited on an aircraft and there are choices to be made. Apparently the decision has been made that J champagne is off the inventory.

I suspect that Qatar may have either been caught in a violation or realized that it as risk. That, of course, translates into "directive from US authorities." It's not legally the case, but it makes sense.