I'm not entirely sure why they're charging so much for the DLC, given that it's cross promotional. That being said, I also don't necessarily think it's fair to compare Microsoft's flagship in-house flight game to Bandai-Namco's; besides the resource disparity, there are other factors at play.
Project Aces, internally at Bandai-Namco, is a crack collaboration project between the elite and senior developers on the BN payroll. However, AC has previously struggled to remain relevant versus all the other very lucrative licensed products they develop; time spent on it must be justified very heavily to compete with resource cost of not working something else.
I'm more acquainted with AC's situation. Full disclosure, I'm also biased (see profile). But I couldn't guess at MS's situation, but for all we know it could be that they value the promotion enough to consider it a worthwhile or irrelevant sunk cost.