Canon Japan released a teaser video for its upcoming 8K video camera. It will be available on their Cinema EOS CXXX series of bodies. The prototype model is out for field testing.
Some time in Q1 or Q2 of 2021, Canon is also expected to announce their top-of-the-line mirrorless camera, the EOS R1. I suspect it will come with unmatched video performance, perhaps in 8K as well and superior to what is available on the EOS R5. Stay tuned for the latest news and development.