Elon offered to allow other manufacturers to join the Supercharger network as well. If Jaguar wanted instant access to the best high speed charging network in the world, they could pay to join and pay a percentage to help expand the network. They wouldn't have to build their own network from scratch.Sure, someone else could build an entire network of stations just like Tesla is. That's not the same thing as Jaguars charging up at Tesla stations like it was suggested here.