Not sure where you're getting that from. Tabata himself said that they cut alot, he insinuated that Versus 13 was originally supposed to have sequels, so he had to cut alot of planned story elements in order to condense the story of of multiple games into a single game. We know that he cut Stella, we know that he cut the Invasion of Insomnia, we know that main villain roles changed almost entirely with Iedolas and Verstael having much bigger roles originally, we know that references to the Godess Etro and Noctis' ability to see the light of expiring souls were cut, we know that Versus 13 was designed to be much darker than 15 ended up being.
And that's just story, we know that Tabata made alot of gameplay changes as well.
Look, I liked FFXV, it wasn't a great game, it had rushed writing, poor combat, and a number of other issues, but it was still a fairly fun experience overall, I gave it an 8/10. But you can't blame me and others like me who followed Versus 13 right from it's 2006 announce for mourning the loss of Nomura's version. Could it have ended up being worse? Sure. But it might have been alot better as well. Fact is we will never know. All we can do is dream.
He did. The Invasion of Insomnia, playable parts of Stella/Luna's trip, an entire dungeon within the Dream World Noctis visited, a dungeon in the World of Darkness as well... The sequels were the only thing Nomura envisioned out of the game, and those sequels were undeveloped, especially story-wise. Almost everything he cut was just more content to make the world a little less sparse, and that ran into the good old problem all Nomura games had: running out of time. Iedolas and Verstael's roles were essentially becoming bosses and leading an invasion/military campaign. This was condensed into Kingsglaive and the Ramuh raid... The references to the light alluded to their current role as the ones who would end the Starscourge and tied in to Ardyn's immortality. The summons weren't there. Worse carnage, bloodshed and a more "total war" tone were the main reason for the game having been darker back then, but the central plot had always been the friends going around and trying to get the Crystal back to protect Insomnia from the daemons.
There was no "vision". That's the problem. People have to accept they would've gotten a more complete product, but our game wouldn't have been different. FF Type-0 for Xbox is still the same Type 0 you got for PSP, but with better graphics and extra stuff.
But no, this needs to stop. There wasn't "more" to this sort of shite.