Famitsu has posted the results of the color poll for BBCF! For those that don't know, each character in BBCF is getting a handful of colors from past games that were selected by vote. The results are posted on Famitsu.
The GGX promotional video and Baiken’s story mode ending go back to the beginning of the franchise, and as you said, a lot has been retcon.
Baiken’s GGXX story mode bio says that Baiken lost her parents during the war, and her GGXXAC+ bio mentions that the death of her parents during the crusades left her traumatized. And again, Baiken’s GGXrd Rev 2 bio says she lost her family during the crusades. It also mentions her homeland is Colony. That pretty much contradicts Baiken’s scene in the promotional video and her GGXX ending if those sources are really referring to Justice initial attack on Japan as you suggest.
Now Japanese are Gears? That would contradict a lot of stuff in official material. I though they become Gears after the transformation, that’s what was stated in the game, it was never mention they were Gear before. The condition that Japanese have has been referred as disease until now.
Well, there was a reason people were confused about him being playable in the first place. His character didn't really fit into doing anything relevant for the plot in an uncontrived way. He needed a plot for arcade mode, of course, so the smacked one together, but there was no way he was going to do anything interesting in story mode without screwing everything up.
Honestly, 'Squandered Potential' can be said of most things in retrospect. How many minor plot points or details were forgotten and never mentioned again, or unresolved? Remember how in CT everyone was supposed to have a 'role' to play, including Carl? Then there's Arakune. What was the point to that subplot? What about the whole replacement black-beat thing? The whole Hazama/Terumi thing was pointless. Honestly I could write a full page on random stuff that never went anywhere, given time.
Also, ...Susano-o was silly and an anti-climatic end to Hakumen...and somehow Terumi himself. Why does Terumi possessing Susano-o cause the suit to grow three heads and a tail? And it was really that easy for him to grab it?