As for X, the other part of the 2/3 new content making up 2.8, even Nomura called the original PC title a spin-off in early interviews (of course, that's after he explicitly and repeatedly stated he wasn't interested in making a game about the Keyblade War, so...). It wasn't intended to have any bearing on the main plot and now that it does fans have to contend with yet more mythological baggage which comes off as increasingly superficial given how casually it's decided that games will be made to "tie into KH3" at this point.
Personally, to me it's a question of merit: is something offered through a game which the story would be irreconcilably different without? I accepted BBS/Days/Coded as a legitimate trilogy which doubled as an experiment in world building, character development and (primarily for BBS) set up for the last chapter in this saga. There was a clear culmination of ideas threaded between all of them. DDD undercut a lot of that imo, and now X/Back Cover appears to be making the case that the series should refocus on a series of events which, sans yet another subversion of the plot as it has been established, should have really limited bearing on anything that has happened thus far.
I'm not in a hurry to get KH3, personally, and I don't really care if the series wants to read like The Silmarillion but there are fans out there who find the retread of the same narrative antics tiresome and I guess I just don't find the series' reputation to be unearned in that regard.
I think I gotta have to agree with this on most points.
With Blank Points from BBS, the ending of Re: Coded and Signs of what's next, Re: Coded's first secret ending, we already
had a setup and prospect for KH III that established both the "rescue the suffering ones" and "return of Xehanort" points to serve as the main driving force.
BBS FM gave us the Fragmentary Passage teaser with the prospect of several gaps in the already existing story being filled and allowing to see the viewpoints of other characters and thus giving them much needed additional focus and screentime.
All the whole X-stuff, no matter how possibly intriguing, cute or well done
does nothing but add further baggage to the already bloated mythology. There are still so many unanswered questions and open mysteries from the previous games that there would be clearly enough material to weave an interesting story out of without needing to add anything from X[chi]. Furthermore, X[chi] also adds yet another bunch of new characters to an already bloated, mostly only half-developed cast of major original characters and makes it even harder to properly focus on the characters as individuals.
I get that Square wants to have a foot in the mobile market, but they could have easily done that by letting X[chi] remain a mostly non-canon, free to play and lighthearted
true little spin-off. Nomura's apparent need to connect everyone and everything to the main overaching story may start to hurt the whole package as the often lackluster writing of the games does not manage to integrate and present all these elements in a satisfying way for the audience.
2.8 could have been easily the true BBS v2 holding
all the potential gap filling material alongside DDD HD and thus have possibly a playable Riku and Mickey in the new KH III system as well.
As for the "movie" part of the package, they could have covered the year Terra-Xehanort was an apprentice under Ansem the Wise with the POV switching between (possibly) amnesiac Xehanort (maybe including some additional mental "battle" scenes between Master Xehanort and Terra inside the new Xehanort, giving Terra much needed screentime and possible more depth), Ansem the Wise himself and either Leon, Aerith, Cid or one of the other FF cameos to provide the view of a regular Radiant Garden citizen.
This would also have allowed more appearances and insight on already existing characters like Braig, Aeleus, Ienzo, Even, Dilan, Isa and Lea and if done correctly water people's mouths for the possible roles all these characters might take in the upcoming KH III.
There is enough material for an one hour movie in this time period as well and they could even sneak in a preview for one or more possible new FF cameos.
The finale of that piece would then obviously be Maleficent's invasion.
Instead we get X[chi] with the usual prophecy of doomy dooms cliché and a cast of characters that is majorily either totally unrelated to the current storyline (as they should all be dead by the current time period) or just another set of clones forcibly "connected" to the main characters somehow.
At least for me, the only universally positive things coming from X[chi] are Chirithy, Apocalypse-Coaty and his damn sass, Skuld and Ephemera.