Beware any manufacturing company that locates the HQ away from the plants.
It's a sign that they want disconnect from the messy realities of manufacturing, and want to focus only on the glamour of money and marketing. Any time I've seen a company do that, they get rapidly FUBAR.
Mind you, you might need to move the plant, too, thanks to greedy/corrupt state/local governments, or unruly labor. But you have to stay attuned every day to the ground floor of your operations.
Boeing has plants across the USA, not only in Seattle anymore. One reason for moving headquarters might have been to give the appearance (only) that they recognize the rest of the company (Meaning MacDac for the most part). They were also having issues with Washington state and local governments, unions, etc.
As to the tanker;
Given the Great OH's international dreams I think Airbus has an edge in DC. And, I think the bias against Boeing goes beyond McPain to include the Air Force in general. They are probably still smarting from being told they screwed up the earlier procurement(s) - so there might not be much of a stir if a new RFP is slanted toward the Euros.