For a game that was stuck in development hell for a decade, Final Fantasy 15 is often considered a contentious but mostly positive entry in the series by fans. As the first true-to-form open world Final Fantasy game, the game handled a lot of things well, but not exceptionally. The world itself was genuinely beautiful and fun to explore, even if the quest design was a bit conservative. The action RPG combat was serviceable, even if it lacked the depth from traditional turn-based combat. However, the biggest detractor of Final Fantasy 15 is the game's narrative design and multimedia approach, something that hopefully Final Fantasy 16 won't replicate.
Alongside the main game, there was a fully animated movie, a limited-run anime series, spin-off mobile games, as well as numerous DLC expansions. The presentation of Final Fantasy 15 was at best overwhelming, requiring an even greater commitment of time to a JRPG, which is typically already a huge commitment. Final Fantasy 15 did have a definitive end, but not without vexing holes in its narrative that were eventually filled (somewhat) by the game's DLC episodes. With Final Fantasy 16 officially on the way for PS5, the game's more traditional medieval setting should avoid the compartmentalized approach that Final Fantasy 15's narrative took.
The Multimedia Arm of Final Fantasy 15's 'Universe'
Final Fantasy 15 came out as three separate experiences when the game released: the base game, a CGI movie, and a limited-series anime. The entire inciting incident to Noctis' journey in Final Fantasy 15 begins the animated movie, Kingsglaive: Final Fantasy 15. Certain scenes are shown in a montage, but that entire story behind Niflheim's invasion of Lucis happens entirely off-screen. The anime is comparatively optional but many of the main characters' backstories and character development, as well as their relationship with Noctis, is established there. Anyone who just played Final Fantasy 15 standalone was already at a narrative disadvantage.
This is why Final Fantasy 15's story was widely considered lackluster at release. The necessity to watch (and in some cases, buy) additional pieces of media, just to get a base understanding of the world and the conflict, was ultimately a detriment to the Final Fantasy 15 experience. Even when fans did watch the movie, the only redeeming factor was its art style anyway. Final Fantasy 15's plot is not made any better with that context. That may have been partially due to the game's long development, and that the best way to cut corners was to release additional media. Either way, Final Fantasy 15 on its own, was severely hampered by its multimedia arm.
Final Fantasy 15's DLC Filled In Plot Holes, Instead of New Stories
Pair that with the missing character background filled in by paid DLC, long after the base game released, and the narrative climax didn't feel well earned at first. Final Fantasy 15's four singleplayer "episodes" focused on portions of the story where Gladiolus, Prompto, and Ignis separated from the main party. The last episode was a DLC expansion focused on the main villain Ardyn's origins as well. All of these DLC expansions filled in existing gaps in the Final Fantasy 15 story in some way, rather than building off the existing story in a meaningful way. Every episode, save for Episode Ardyn, can be boiled down to "why X party member left for a while in the story."
Story-based DLC like these episodes should've been supplementary experiences, rather than complementary. Hardcore fans should feel satisfied that their Final Fantasy 15 experience is enhanced by these expansions, but they shouldn't be a requirement to enjoy the overarching narrative either. That's not to say all fans weren't satisfied by Final Fantasy 15's story, but it's no secret that these expansions were a complementary addition to the existing narrative. Final Fantasy 15's base game framed each DLC as a period of time where each character was separated from the party for a short time, with little to no context in the base game explaining why.
Final Fantasy 16 Expansions Should Be Supplementary, Not Necessary
Obviously, at the moment, there's no way to know for sure whether or not Final Fantasy 16 will take the same narrative approach. However, considering the last episodic DLC content for Final Fantasy 15 ended up being cancelled as the game's new director left the project, it's not likely. Square Enix utilized a season pass-style expansion plan for a singleplayer JRPG, along with another additional four planned episodes coming to the game later on. Only one of those, Episode Ardyn, saw the light of day, and now Final Fantasy 16 is finally underway. Square Enix may consider DLC expansions for Final Fantasy 16, but it shouldn't be anything like Final Fantasy 15.
If anything, as mentioned earlier, DLC for the next game should be strictly supplementary. Players will likely be able to start and finish an entire cohesive story in Final Fantasy 16, without turning the sixteenth game into an investment of time and money. There doesn't need to be an entire Final Fantasy 16 universe, at least in the same vein as its predecessor.
Final Fantasy 16 is in development.