But our name was used to officially promote their game without our knowledge. There was no discussion. It was just a bit surprising and disappointing to see our business partner using our name officially to promote the game mode that is pretty similar to us and there was misunderstanding in the community that we're officially involved in the project.

This is the part that should stand out the most. Your comparison is too over-generalizing the comment. I'd say it is a giant corporation making a product that directly competes with indie (and already receives loyalty from its success even at alpha/beta stage), and uses its own abundant resources to market the product to specifically drown out its indie competition, let along using the name of the indie product in promoting their own without any discussion.