FOSS wasn’t specifically mentioned, but jailbreaking was. I’m sure most FOSS stuff would be fine, passed a certain point like you said. I’m from an era where jailbreaking and installing whatever you’d like on a device was the wild west, and have seen nasty stuff accidentally sideloaded. Giving people the option to infect their cars with ransomware could get people killed, so not opening that can of worms isn’t the worst idea necessarily.