Sony includes this feature on cameras without interchangeable lenses (ie: "point and shoots"), and on their high end cinema cameras, but not on their mirrorless (interchangeable lens, but not considered cinema cameras) line.
Seems pretty clear this is designed to avoid their mirrorless lineup have a feature that might make it competitive with their cinema line. But they're ok including it on the point and shoot line because that already is well differentiated from the cinema camera line.
It's been over a decade since I really followed the digital camera scene.
At the time, DSLRs were just beginning to get 1080p/720p video capabilities. There were frustrating time limits of course, even then. But, I recall that some of the cameras heated up pretty significantly when capturing video. This was sometimes cited as a reason for such time limitations on video recording.
I'm not sure if that is possibly a "legitimate" physical reason for the limitation today, or if it ever was in the first place. Any thoughts on that?
A Cinema body has a lot more room for heat sinks, and can more easily accommodate fans - you're a lot more likely to be using an off-body mic on the cinema body. And then you have a larger battery for the chips and recording time.
And yet, you'll still see cameras on hot sets with bags of ice around them because these heat sinks and fans cannot keep up. The original Red One was notorius for overheating. I have BMD Ursa Mini that was struggling in 105 degree temps. Big body does not mean over heating is solved. Personally, the camera that I've used that best handled heat was Sony's F55. Shooting interior of an old van with sun beating down through a window in the roof directly on the camera, 110 degrees inside the van (yes it was miserable), and the camera never once complained (unlike the cast&crew).