Speaking to Car and Driver, this was confirmed by Volkmar Tannerberger, head of electrical and electronic development at Volkswagen. According to Tannerberger, “We wanted to demonstrate wireless CarPlay and the owner of CarPlay technology didn’t allow us to.” It is unclear as to why Apple wanted to block this from happening.
However Car and Driver speculates that this might be because Apple either wanted to show the feature off on its own terms during WWDC or a separate event, or they might have inked some kind of deal with another carmaker whom they’d prefer be the one who would show off the technology.
It’s an odd choice because like we said, wireless CarPlay is a feature that was introduced in iOS 9 so it’s not like it’s new, so there is already a good chance that iOS users are familiar with it, or at least the ones that have CarPlay systems.