Actually no, Ghosts of Tsushima was a part of the spotlight-announcement, not Days Gone.
"This year, Sony is planning something different for the PlayStation E3 2018 Showcase, which starts on June 11 at 6 p.m. PDT. Instead of rolling out numerous trailers, the keynote address will focus on four PlayStation 4 exclusives. These games are Kojima Productions' Death Stranding, Sucker Punch's Ghost of Tsushima, Insomniac Games' Spider-Man, and Naughty Dog's The Last of Us Part II."
Oh! That explain it then. Got it muddled up in my mind, wasn't expecting to see much of Ghosts at e3... xD