The Washington Post won’t say why it cancelled a six-figure ad buy calling for Elon Musk to be fired, but it’s likely the same reason the Post insisted Musk wasn’t Nazi-saluting on Inauguration Day, and why the paper killed its endorsement of Kamala Harris: because that’s what Jeff Bezos wants.
All of their businesses work together. Many of their staff have relationships at the opposing organizations. There’s just not much to gain for these guys when it comes to burning bridges with each other.