The final Trophy on the list is a Gold one that is achieved by completing the episode called Farewell. This bonus episode is exclusive to the Deluxe Edition of the game, and doesn't come with the base version.
Now this may not seem like a big deal to those who aren't interested in Trophies, but for those who are, purchasing the wrong edition could make getting the Platinum Trophy an impossibility. The Farewell episode could be made available separately after release, but at the time of writing, this is an unknown quantity.
So Trophy hunters, make sure you're buying the correct version. Do you think this is unfair? Let us know in the comments below.
Update: Square Enix has sent us the following statement with regards to this story: "This was a mistake on our side and not our intention to gate the Platinum Trophy via the optional Bonus Episode in the Deluxe SKU. We've already started speaking to the first parties about rectifying this."
Fortunately, it appears as though this was an error after all. Phew.