When they demonstrated a wired-in attack on those vehicles at the DefCon hacker conference in 2013, though, Toyota, Ford, and others in the automotive industry downplayed the significance of their work, pointing out that the hack had required physical access to the vehicles. Toyota, in particular, argued that its systems were “robust and secure” against wireless attacks. “We didn’t have the impact with the manufacturers that we wanted,” Miller says. To get their attention, they’d need to find a way to hack a vehicle remotely.

But you are apparently ignoring this paragraph, which discusses Chrysler responding to the hack, as I read it, prior to the events in the article:

Second, Miller and Valasek have been sharing their research with Chrysler for nearly nine months, enabling the company to quietly release a patch ahead of the Black Hat conference. On July 16, owners of vehicles with the Uconnect feature were notified of the patch in a post on Chrysler’s website that didn’t offer any details or acknowledge Miller and Valasek’s research. “[Fiat Chrysler Automobiles] has a program in place to continuously test vehicles systems to identify vulnerabilities and develop solutions,” reads a statement a Chrysler spokesperson sent to WIRED. “FCA is committed to providing customers with the latest software updates to secure vehicles against any potential vulnerability.”

The way I put the information in those two paragraphs together, it's the fact that the attack can be done without physical access to the car that got the attention of Chrysler, not the publication of a stunt in some web rag.