It will be a win for Boeing of course, as there is no real alternative in a duopoly if one supplier does not supply a customer anymore. However, that will be quite costly for Qatar in the end, as Boeing has absolutely no incentive anymore to give big discounts, after all where is Qatar to get any alternative? By the way, Boeing did pull a similar trick at one point, by openly refusing to sell aircraft to a company which was then forced to completely switch over to Airbus over time. That airline does not exist anymore, but the cause of that is quite an unrelated story.
That said, with the current
state of the game (2020,
2021), Airbus can actually be quite relaxed about the whole thing. Not to mention that Boeing has no real answer to the A321 LR and XLR.