The adoption of CinemaDNG among camera manufacturers appears to be hindered by Red Digital Camera’s patent US9245314, which covers in-camera recording of lossless compressed raw video. There had been an unsuccessful attempt to invalidate the patent.
Even worse is that Red simply ripped off JPEG2000 and got a patent on it.
The patent "system" has become a tool for exactly what it was supposed to prevent: the theft of people's work.
IP expiration dates are a "brain plasticity" parameter in society. Higher values mean lower rates of change, too low values mean too high rates of change. Twenty years is a sweet spot.
Now if a new patent is filed the patent office cannot ignore it as prior work. While the bar for machine generated patents is high. There is IMHO no reason why prior art cannot be machine generated and if something very similar can equally generated by a machine it becomes even more questionable if something is patentable at all.
Besides that, what you describe sounds like a decision made to reduce weight of the camera module, possibly not related to patent.
Yes, the Inspire 2 does this, and it was widely reported that this is how they dodged the BS patent. The weight distribution may also be another bonus, or vice versa.
I actually don't know why there's this perception that the patent only applies to camera-internal compressed raw, because Apple/Atomos have to pay Red royalties but Atomos recorders are obviously external. But you hear it over and over.