[davidmanze]

Well, the main problem for the K3 replacement is the lack of a new sensor offer. We've been stuck with the the base 24 mp Sony sensor since ~2011; there have been improvements, but they were mainly for mirrorless cameras (on-sensor PDAF for example).  This, combined with the rapid decline of the camera market, means you simply can't keep up the "new camera every 1-2 year" cycle of the 2000s.

I mean, what new & exciting features can Pentax offer in their top of the line APS-C camera?

The K3 II dates from April/May 2015 so that's very nearly four years.
 
   I'm sure you can still find a K3 II but it is out of production so it's really down to the KP. I had the K3 I which was a fine enough camera......but to me the KP is a down grade albeit with lower noise.

  K3 III could have the:

  better AF-C of the K1 II.

  lower noise sensor of the KP.........(they have the parts already)

   and just a few tweaks.

  I just can't see that waiting a further year was/is a good plan!