We wrote it for weeks if not months: Canon might announce a full frame mirrorless camera before Photokina 2018 (September).
Now others seem to have come to the same conclusion and are suggesting Canon might announce one of the (supposedly) two full frame mirrorless cameras they have on their agenda. It’s just 10 weeks to Photokina 2018, so, if an announcement in September 2018 is to expect, then very soon we will see serious leaks instead of speculations. The only thing sure so far is that Canon will announce at least one full frame mirrorless camera between now and Q1 2019. It’ sure it’s coming but no one knows when.
To get the point (and latest updates) about Canon’s full frame mirrorless camera have a look here.
All Canon full frame mirrorless rumors are listed here.