Why are you assuming the marketing team could do whatever they want and then management just goes "guess we're doing that now"? Did they hold the directors (or whoever they got in front of the camera) at gun point to force them to say they're going to do things they weren't planning to do? Even if we somehow accept that are true it still opens up the question of why wasn't this then properly planned into the roadmap and have timelines adjusted? Or did the marketing also dictate the timeline?

It's more likely marketing also did what management told them to do and the poor management is what got us the bad marketing material and poor quality product.

We can agree that management was the issue and that marketing generally sucks (I've had first hand experience where marketing/sales fucks over the devs because they never even talked to us, with normal management that happens only once), but I don't think you can or should blame marketing to the extent that you have.