I can only repeat myself from another thread:
Well that happens when you change the story every 3 months and release random trailers at the same time.
That E3 2013 stuff wasn't surprising to see getting cut/ played out totally different in the final game even though it's probably the trailer that got the most people hooked on XV. However... there's really no acceptable excuse for all the scenes from the TGS 2014, Jump Festa 2015 and Dawn +2.0 trailers that didn't make it in the final game.
I'd just love to know what happened behind the scenes and why they ended up heavily promoting a game that never really existed. I mean they at least rebooted the game like four times:
2006 - 2011 : showing off versus XIII (the story script was finished in 2010. 2006 was not representative for the game either and was only meant to set the tone)
2013 - 2013 TGS: introducing XV -> an expanded version of the versus XIII story (a world of the versus epic)
As stated above according to Ferrari they changed the story during that time pretty much every 3 months.
after that -> restructuring of the team once again and setting a tight budget and release schedule for the game.
TGS 2014 and Jump Festa 2015: Introducing the new condensed version of XV under Tabata -> Luna as the new heroine, slight design changes (Prompto) (world of the versus epic tagline is no more)
After that they must've made a lot of adjustments because of Kingsglaive.
GC + TGS 2015: Introducing the new Regis design -> heavy focus on the bond between father and son and Noctis' "prophecy".
-> They rumourdly changed Luna's story after that because they were afraid of the feedback that would've caused the original story ( The trailer hints at child abuse but tbf that scene was never properly explained.)
Note:
Nothing from the Dawn trailer made it into the final game)
March 2016 Uncovered: It seems like they finally had the story complete, also kingsglaive was done at that point. (Even though they still showed some scenes that never made it into the game ->probably due time constraints).
Interesting to note: They only decided on the details of the season pass content ( and the idea of a season pass in general) after the Uncovered event even though they already said before that there would be dlc in some kind of form for the game.
So it seems like they didn't have a final plot written until late 2015 at least which is absolutely crucial and also still had to cut some stuff because they ran out of time.
I really hope we'll get the whole story of this development & marketing desaster at some point in the future in 20 years or so :x, it's just too interesting to know what really happened.
I also did a compilation video of everything that's not in the final game:
A fantasy based on misleading trailers