So yeah this is a thing

we don't really get a sense of how time passes in Quadratum compared to the main KH-verse, but the Missing-Link leaked opening and what we know of the game suggests the intention is that this has been happening at the very least since then - and Sora showing up might have made it worse

(given it's implied Ava has been here this whole time, Dandelion Dispatch might have been setup by her?)

but this raises the question of how Yozora factors into all this, and why he has a weapon that can incorporate a Keyblade (i had originally assumed it was capable of incorporating potentially any weapons, but these new revelations suggest to me it's specifically for Keyblades), like is he part of this military that works alongside the Dandelions, with a specialised tool designed to incorporate a Keyblade in an emergency and use its abilities, bypassing that he's not one of the Keyblade's chosen? or is he part of a faction that is against the Dandelions and wants them gone because of the effects their influence is having on his world? (is that why he's wearing a patch with a skull and crossed keyblades?)

and then how is Luxord factoring into this, we know he works under Yozora, but we don't know if he's from Quadratum or if he originates from the KH-verse (presumably as a contemporary of Sigurd) - we know he's tied to the "ancient Keyblade legacy" or whatever somehow, but does that mean he's actually a Wielder, or is it his involvement here going up against Wielders - did he lose his heart on this side of things, and because Quadratum works differently, his body was transported through into the main KH-verse to become a Nobody?