I doubt that... IMO, Pentax (or the rest of MF companies that are using the sensor) is simply inexperienced to other than commercial video and thus are not (yet) capable to take full advantage of the sensor's capability... IMO, Sony did make the sensor aiming it to large format video (as to stay on part with cinema's recent developments)... the reason they don't use it yet on a camera of their own, has (IMO) to do with the mount they use (the E-mount) which is universal to all their products, commercial or professional... OTOH, this doesn't mean that there is no research happening in the labs...
Sony professional video cameras support industry standard PL mount, which covers movie 35mm (more like still APS formats). They do use E-mount on some of the prosumer models.
I simply don't believe that Sony would ever bother with a sensor as to make only a few of them annually (which may mean that it's not any profitable... if not the opposite)... Lets not forget that Cmos sensors are cheaper than CCD to make, but they are considerably more expensive to develop and put in production... Other than that, having a sensor that has "just" the pixel size as to deliver 2,4 & 8k video in its long side but 1.5, 3 & 6K video if cropped down to 32.8mm (which would fit ideally in the E-mount) width and the shorter side of it is used as base ...can't be accidental with Sony! ...remember it's Sony we are talking about.... not Dalsa!
Sony makes a lot of sensors, and many of them get very little use. I'd say this one has been particularly successful for them, considering the low yelds they must have. The bigger the chip, the less you can fit on a silicon wafer and the more catastrophic small issues in manufacturing can become. A tiny mistake can lead to one or more sensors having to be discarded, and when you can fit only 20 or 30 of them instead of the hundreds or thousands of smaller formats it does get expensive really fast. R&D on CMOS sensors is no different than CCD, and Sony has that covered thanks to decades of experience on the matter. Each new design has been most probably already paid in full by previous models, and even if they don't get to sell it's still experience they can put into newer stuff.
Yes, the sensor happens to have the requisite resolution for up to 8K video, but does it have the right on chip electronics to support such a high data throughput at even 24 frames per second? We don't know. It would also need a beefy processor as well as some seriously fast storage to be usable.
Sorry, but the E-mount is a tight fit even for a 36x24mm sensor. It will never be able to fit a 43x32mm one without losing all four corners.
If Sony really wanted it to be a video sensor, they would've made it in a different aspect ratio right from the start. It makes no sense to manufacture all the extra pixels if you don't use them, plus if you make the sensor height shorter you can fit more of those on a silicon wafer reducing costs.
If you are wondering, then, why the Alexa XT and VistaVision are 4:3 (or close by), it's because the former supports anamorphic lenses (and having a bigger sensor helps in not losing resolution) and the latter is a native anamorphic format.
Anamorphic video bigger than 35mm has always been more of a rarity, and after IMAX there was no need for it anymore. Keep in mind that an anamorphic 65mm lens would cover about a full frame 36x24mm sensor, so again no need for anything bigger.
All the signs point away from a video centric sensor. It's more of a general purpose sensor that can take stunning pictures and even manages to be fast enough for video (under certain conditions and limitations).