Boeing treats the entire McDD product line as though it was their own. For example most airlines refer to the MD-80 as the Boeing MD-80 now etc, etc.
Have you really ever heard ANYONE refer to a "Boeing DC-8?" If so, did you laugh in their face? I would.
How about an Airbus Caravelle or an Airbus BAC-1-11? Makes as much sense as an "Airbus Concorde" which is where this discussion started.