Canon News has uncovered what looks to be new designs for the speciality cameras the Canon ME200S-SH and the Canon ME20F-SH (which is listed as discontinued at some retailers). If you're unfamiliar with theses cameras, the ME20F-SH shoots in 1080p at up to 4 million ISO. The ME200S-SH is the “affordable” version that shoots to 204,000 ISO.
There seem to be new connections on each camera design and I imagine any updates to either will bring 4K recording. I also wonder if the mount is interchangeable on one of the cameras because of the 4 screws on the front of the new design. There looks to be enough space to swap out the EF mount for an RF mount. Or more likely, being able to swap EF and PL mounts on your own.
Possible Canon ME200S-SH Replacement:
Possible Canon ME20F-SH Replacement: