It used an existing implementation, in theory this was mostly a porting task.
GPL-wise, I don't know how much is inspiration vs "based on" would this be, it'd be interesting to compare.
This looks like my Company peers, as long as there is any existing implementation they are pretty confident they can deliver, poor suckers that do the "no one has done it before" first pass don't get any recognition.
Personally, I'm not demanding to enable tinkering on everything if that's raising prices, it could be as simple as having some "This unit is serviceable" label, I'd let people to value it and manufacturers to follow it.
TBH, I think most people wouldn't care, specially in USA, it is way easier and cheaper to replace than to repair, workmanship is really expensive here.
But If a manufacturer shuts down a Cloud service that bricks my device they should open the interfaces and protocols to make them functional.