This is much ado about nothing based on a single local dealer's attempt to get some attention.
Photokina was scheduled to take place May 27-30, 2020. It was expected that Canon's official announcement of the R5 and R6 would take place in conjunction with Photokina 2020. Any pending official product introduction for the R5 will not be "late" until May 27-30 have come and gone without such an announcement having been made.
We've since learned that the R6 announcement will not happen in May, probably due to supply chain issues and Canon's apparent decision to place what resources they have available into getting the R5 launched. As of yet, we've heard no such rumblings regarding the official rollout of the R5. Unless we do, I'd expect Canon to make an official product introduction for the R5 sometime at the end of May.