Why is Yen Sid's "important" book you're told to read in KH II just a bunch of gibberish? Even reading it with newfound knowledge, it doesn't really say anything aside from some very general "don't give up hope" metaphor.
And he tried to make Sora of all people reading it.
“Keyblades wielders from all over will flock here!” Vanitas said.
WELL WHERE ARE THEY VANITAS? HM?
*Sora uses the Union X Keyblades from the past to defeat the Heartless*
*Vanitas, screaming in the distance*
"See? See? I told you! You all called me crazy! Well who's crazy know, huh?!"
*He says as he keeps hitting on Xemnas' shoulder and nudging an unresponsive Xion*
Right, so initially the plan was to create the X-blade (using the clash between light and darkness, so what we got in KH3 was clearly not initially planned to be THE war according to earlier statements given by the characters) and summon enough Keyblade wielders (via using the newly forged blade to provide them with transport to the battlefield) in order to prompt a second, genuine war, and from there they would see what became of the world after. See if they were worthy of the "precious light the legend speaks of." That was Xehanort's stated endgame in BBS, correct me if I'm wrong, so I don't know where this whole using the X-blade to "purge" the worlds and reset them to a blank slate came from ,in KH3. The statements and logic given just doesn't track to me. Where was this information back when he was explaining his goals in BBS? Mind you, 80 percent of what little Master Xehanort says in KH3 is taken word for word from BBS (the redundancy is mind boggling), so what changed? DID anything change? Why do I even have to ask this question? Such a head scratcher...
Maybe this is what Nomura meant about Xehanort's character changing. From wanting to gather Keyblade wielders to re-enact the War and conjuring the Darkness and the true Light, to summoning the X-Blade to reset everything because people are bad.
So he basically went from Hellsing's Major to Zamasu, and I can't really say it was an improvement.
The only thing that works in Nomura's favour is that minus Maleficent's one line they never really tried to sell KH III as a "Keyblade War".