New Rumor: The DSLR is not dead yet, 5D Mark V apparently in development

Even though the bottom end has dropped out of the Canon EF sales, Canon still has a good reason to continue with DSLR development.  60% of all cameras shipped these days are still DSLR's.  While the mirrorless (especially full frame) cameras are experiencing growth, that market is also growing because there's simply more companies building full frame mirrorless cameras in the last year.

According to Canon Rumors, the 5D Mark V has appeared on an internal roadmap for Canon, as well as the EOS R Mark II.  No word on when the camera will appear or to what it will contain.

The 5D Mark IV replaced the Mark III version after 4.5 years on August 2016, making a spring to fall release in 2021 most likely for the 5 Mark V. With all that Canon wil most likely release next year, it's certainly doubtful that a new 5D series camera will make an appearance in 2020.  The 5D series most likely takes around 3 years to fully develop, so Canon would have to be well into development by now for a 2021 release.