Should be remembered that the info revealed so far is not so much an 'announcement' as much as it's an announcement that an announcement is imminent!
From memory most if not all manufacturers do this kind of thing.
Nikon did it for the Df and the D850(AFAIR) and Pentax also did it for the K1(way back when).
Tidbits of info close to Photokina, then the announcement proper comes about a month prior to Photokina, products go out to the various review sites, they do their early preview stuff .. basically reducing the cost of the manufacturers marketing budget by a few mil
create a few ripples of anticipation on the net, in no time those ripples turn into waves ... fanbois argue for, non believers argue against ... maintains internet chatter for as long as possible, maintaining a high online profile for as long as possible for the manufacturer and product.