The announcement date guesses for Canon's first full frame mirrorless camera have ranged between Photokina in September 2018 and some time in Q1 of 2019.
We're now told that one of the full frame mirrorless cameras coming from Canon will be announced and on sale before the end of 2018. While the exact announcement date is unknown at this time. Logically, something should be happening for Photokina. Although, we're a mere 10 weeks away from Photokina and specifications are still hard to come by, if more information doesn't become clearer soon, we might only get a development announcement at the trade show.
We have noticed a spike in folks seeing cameras being tested in the wild that don't match up to current Canon camera bodies, unfortunately we have yet to receive any pictures of suspected test cameras.
Nikon appears to be getting closer to announcing their new system and I don't expect Canon to be too far behind.