Of all the games without specific dates on this list, this is the one I really wish had a date. We're all well aware of the development hell that surrounded The Last Guardian, and so a concrete release date would give us a lot more faith that this game might actually be released. That being said, I highly doubt Sony would have re-revealed the game without knowing it is near completion.
It's hard to disassociate The Last Guardian with its 5-year disappearance, although it's interesting that nobody brings that up about Ni-Oh. The Last Guardian is the spiritual successor to Shadow of the Colossus, which in turn, is a spiritual successor to ICO. Those two games, from genius creator Fumito Ueda, are some of the most beloved in all of PlayStation history, so it's no wonder that fans were supremely excited about The Last Guardian, and extremely disappointed when they thought it dead.
So, it was with open arms that the PlayStation community welcomed back The Last Guardian at E3 in June. The game was re-revealed with a gameplay demo that showed a nice section that should represent the moment-to-moment gameplay of the entire experience. Much like What Remains of Edith Finch, we know surprisingly little about The Last Guardian but, hopefully, we hear some news, including a release date, very soon.