I have been told that Canon will introduce not one, but two 8K Cinema EOS cameras in 2021. One of the cameras will be a flagship camera with “A camera” aspirations, likely in the form factor of the Canon Cinema EOS C700.
The second one I have been told will be a more modular camera in the same vein as the Cinema EOS C300 Mark III and Cinema EOS C500 Mark II. Where it exactly fits into the Cinema EOS ecosystem is unknown at this time.
I don’t expect an announcement until around the NAB 2021 timeframe, which usually occurs in April.