We haven’t received any release dates or even a window for Ghost of Tsushima yet, but according to a presentation for Sony shareholders it’s listed for a 2019 release.
After Death Stranding received it’s release date in May we were expecting to see the Last of Us 2 release date come next. The assumption from many outlets was that Ghost of Tsushima would not release until 2020 given the lack of information. At the moment, there is still a big question mark for a confirmed release date but this document has certainly fueled speculation.
This should be treated as a rumor as memos like this have “leaked” from Sony and Nintendo in the past and found to be fake. If true, this would place two exclusives from Sony in an already crowded Fall. 2020 is shaping up to be a big year for both software and hardware, and it would likely make more sense to hold off till then to sustain the hype.