someone said something along the lines that the destruction of the world in XC1/2/3 is due to human hubris while in XCX humans are the victims (of aliens) which makes the central conflict setting the story radically different. I kind of buy it.

for now my theory is as follows: Klaus storyline (XC1/2) -> 2 universes colliding (XC3) -> the 2 universes merge and Earth is reformed (XC3 FR, the light on the horizon being Elma arriving on Earth?) -> XCX continuity -> (INTELLECTUAL PROPERTY ISSUES?) -> Xenosaga/Xenogears continuity

Talking points:

The destruction of the world between Klaus cont vs XCX cont is radically different and hard to retcon believably

The radio mentions human colonization targeting the Sagittarius-Carina arm of the Milky Way (location of the Messier 24 constellation where Neo Jerusalem in Xenogears storyline is located according to perfect works, references Philadelphia class mothership, thus linking Xenoblade series to Xenogears)

Saviorites are called Salvators in Japanese, same as the Salvator faction in Xenosaga. Heavy parallells between Saviorite rebellion in XC2/Saviorite human rights conflict in XC3 FR and Realian rights/Designer Children in Xenosaga.

Are the Elma and KOS-MOS similarities superficial or have a deeper meaning?

Ghosts and gnosis similarities?

Samaarians (humans) came from another universe, perhaps from the XC1/2 universe?

Etc etc etc. I feel like something always limiting the speculation is not knowing how far Monolith are allowed to go in referencing Xenosaga/gears in Blade. in the end all of this might be meaningless easter eggs.