The Square Enix site has been updated with a new developer blog that announces free content coming to Final Fantasy XV throughout the comign year. At the start, players can expect to find "enhancements" to Chapter 13 and then to dive deeper into the overall story and for players to gain insight into character motivations.
Other things being brought to players for free:
- making new playable characters
- customizable avatars
- the ability to bring stats over from previous play throughs
- add items to bring new game play options including low-level runs and god mode
- readability tweaks (font size etc)
- real-time content like new bosses
- new rewards and achievements
- limited time hunts
Read all the details on the Final Fantasy XV site.