There have been rumors (from this site) that Canon doesn't have any plans to further develop the EOS 5d line. So there won't be a 5d Mark V. I hope they are wrong.
This camera (R5) sure seems like the 5D5, and seems it has been stated that there will not be a DSLR version of it by Canon. They said via allegedly reliable sources there may be some other camera for that audience. Could be the 5DsR gets an update. I'd probably buy that and either keep the R5 or sell it. The EVF has a ton of benefits and looks better than any EVF I have ever tried, but I still like an OVF and larger body. Mirrorless is in some ways over rated. At the least the bodies should be larger.