ANY online device? Even assuming AI can find vulnerabilities in every operating system, there's no indication that this is actually true beyond a "here's how it could work"
This is the same nonsense that lead to article saying researchers had created a wormhole when all they had done was draw one.
I have a microcontroller with an ROM disk (i.e., physically read only). You're telling me that an AI can find a way around the physics of not being able to mutate ROM and exploit it?
I mean, if it's online it has a network/wireless card and a TCP stack along with at least some amount of RAM, so yea, in theory unless the programming is perfect it could be exploited. Now, it's not going to be used to run AI, but could very well get used in a DDOS or something like that.