We’re told that Canon is exploring making an EOS-1 style body with the latest (or variation of) 50.6mp sensor by Canon. “Exploring” doesn’t mean it’s going to happen, and it won’t happen before the EOS-1D X Mark II is announced.
The sales of the EOS 5Ds & EOS 5DS R will ultimately decide if Canon makes a higher priced version of the camera. There’s been people over the years that have never felt the amalgamation of the EOS-1 line was going to last forever. There are ergonomics attached to the EOS-1 bodies that a lot of people have a hard time moving away from.
I would suspect what the pros have to say about the EOS 5Ds will have an influence on whether or not such a camera gets produced.