Interesting concept … not sure about the filter slots though, possibly too much opportunity to introduce dust onto the sensor

Bit of a "rock and a hard place" really … retain the Pentax K mount, with all the bulk overhead of the now disused mirror box, or start from scratch and produce a slimmer (less thick) body, with a newly designed and manufactured range of lenses to fit, then try to compete in an already over-crowded marketplace. To encourage existing Pentax users to buy, there'd also need to be a fully-coupled lens adaptor at a "sensible" price. Charging a three-figure sum for a metal tube with a few contacts in it is a non-starter, as has been demonstrated in the past!
Presumably, by making the body slimmer (narrower), you'd anticipate using a smaller battery, with the associated loss of capacity