Great FAQ, answers a whole lot of my initial doubts.
Gosh, this seems so complex. On the 1 hand, kudos for PSO2 Meseta keeping the original game intact so that there won't be a riot over fluctuations people do not like. However on the other hand, since they are remaking base PSO2 visuals anyhow, I wish they'd only go 100% and synchronize personality models entirely. Giving old players a few free fashion items and unlocks would be enough to bribe everyone to take the new system.
Synchronizing 100% character models doesn't seem easy. The dilemma is that the older outfits and coating use are modeled to fit the old pso2 body. That is not likely to happen. I mean that I would be willing to shed a certain percentage of these cosmetics to keep things intact across variations. Provided that there's a steady feed of cool new things to replace it, I don't mind. I constantly rotate out my old appearances anyhow. Provided that the character models translate 1:1 it'll still feel just like mine.
I would envision a large complication to this involves a great deal of the cosmetics from the Japanese side of things which were exclusive to collaborations, promotional events, and events that no longer exist. The instance I can think of is the Monster Hunter Frontier Z cooperation where I can envision the clothing and weapons could definitely be given a visual upgrade together with everything else but that I don't exactly know how the licensing or the way the lawful side of the cooperation works where I would wish it was as simple as Sega going through and updating the resources but I don't understand about how much of Capcom is involved in that process.
The same applies to collaborations like the Final Fantasy XIV cooperation with Odin (which exists as far as I know) where I do not know just how much of Square Enix is involved that for Sega to have the ability to update assets . When it was only just Phantasy Star-related things (such as character outfits, cameos from other games, or other Sega-related properties) I could envision that this likely would have been done, or would be done. But from the Global variant we already don't have the presence of buy meseta pso2 Cougar NX so I do not know if there are additional complications regarding Sega's own properties which may also contribute not to updating everything they can within reason.