IFF they do another K-mount mirrorless, many would expect a shortened FFD variant of the mount.
But as that would require a complete new set of lenses, that would only match that line, I would doubt it happening.
Pentax classic film lenses make REALLY good budget Cinema Primes, and can handle being used in front of 1080p thru to DCI4K cameras, in M4/3, S35 (APSc) and FF.
For me, ideally, a Pentax equivalent to the Sony NEX-VG30 or NEX-VG900, would be a sight to behold.
A body like that, capable of doing raw stills (just like the Sony's), with the sensor from the KP, plus Sensor Shift for stabilization, recording HD and 4K at the same data rates as the GH5, would be, as they say, disruptive.
I know I say it a fair bit, but if Pentax could properly carry over the quality of the stills images in to the recorded video, and have a decent quality recordable HDMI output, they would really shock the market.
The K-01 changed the game, without it, Canon would never have done the EOS-M series, and the K-01 proved Mirrorless without an EVF was also acceptable to customers in large sensor formats.
Look at how many similar cameras Panasonic and Sony do now - the GX line from Panasonic, the a5000 thru a6500 from Sony - All Interchangeable lenses with no EVF, as is the EOS-M.
Of the major manufacturers, only Nikon doesn't have large sensor a Mirrorless range for their main lens series.
And only Pentax doesn't have a 'pure' video model.
(Though Nikons action cameras don't really count, if you've seen the video files, you'll know what I mean)
A K-02, 'Camcorder' shaped, with the latest sensor tech, proper SR in video, proper HDMI, recording 4K at 200mbits, focus peaking, stereo audio inputs with level display, WR sealed, and sold at a price between the K-3ii and the K-1, would challenge anything below US$5000.
Heck, the Muted profile is already pretty close to a cinema 'flat' profile. If I could record that on my Shogun,....