It had nothing to do with being iOS or not. A law created for mobile OS would likely apply to other products/industries i.e., if cross-manufacturer licensing was banned for mobile OS, similar types of laws/bans should be applied to other markets under comparable conditions.
I was using CarPlay more as a hypothetical. If, for example, it was declared that CarPlay and Android Auto were a duopoly in the automotive telematics market comparable to iOS and Android in the mobile OS market, laws that applied to the mobiles OS market would/could also apply to the automotive telematics market and vice versa.