The article is extremely alarmist and is extrapolating scenarios from a very limited set of quotes to the point of absurdity.

Specifically the quote: "We’ve inadvertently created a weapon that nation-states can use against our power grid".

So someone broke into an Electrify America billing kiosk. There's no evidence presented to suggest that this would cause anything more than a potential risk to billing/customer data -- which certainly is a problem, but is substantially less of a problem than taking out power for a region.

I'm assuming the actual charging equipment has physical, non-remotely-controlled safeguards.