Ricehigh speculates that the pentaprism housing of the new Pentax APS-C flagship DSLR camera could have a newly developed hybrid OVF/EVF finder:
What’s Inside the Pentaprism Housing of the New APS-C Flagship?
I believe more so it is a hybrid OVF/EVF finder with the existence of a new unmarked secret button at the rear top left (where used to be the playback button on the K-3 and K-3 II) plus a new infrared proximity sensor under the viewfinder, which is a standard design for automatic EVF/LCD on/off toggle switching for mirrorless bodies equipped with EVFs.
Via Ricehigh