Gosh, this seems so complicated. On the 1 hand, kudos for keeping the game intact so that there will not be a riot over fluctuations people do not like. But on meseta pso2 the other hand, since they are remaking base PSO2 visuals anyhow, I wish they'd just go 100 percent and synchronize personality models completely.
Synchronizing 100% character models does not sound simple. The dilemma is that the old outfits and layer use are modeled to match the older pso2 body. In order to synchronize it, they'd have to recreate from scratch (haha pun) 8 decades of cosmetics. That is unlikely to occur. Well, I mean that I would be willing to drop a certain proportion of those makeup to help keep things intact across variations. Provided that there's a steady feed of cool new things to replace it, I do not mind. I always rotate out my older looks anyhow. As long as the character models translate 1:1 it'll still feel just like mine.
I'd envision a massive complication to this involves a great deal of the cosmetics from the Western side of things which were exclusive to collaborations, promotional events, and events which no longer exist. The instance I can think of is the Dragon Hunter Frontier Z cooperation where I could imagine the clothing and weapons could definitely be given a visual upgrade together with everything else but that I do not exactly know how the licensing or how the lawful side of the collaboration works where I'd wish it was as simple as Sega going through and updating the resources but I do not know about how much Capcom is involved in this process.
The same is applicable to collaborations such as the Final Fantasy XIV collaboration with Odin (which still exists as far as I know) where I don't know how much Square Enix is involved in that for Sega to have the ability to update assets there. If it was only just Phantasy Star-related things (like character outfits, cameos from different games, or alternative Sega-related properties) I could envision that this probably would have been done, or would be carried out. But from the worldwide version we don't have the existence of Cougar NX so that I don't exactly know if there are additional complications seeing Sega's properties which may also contribute to not updating everything they can within reason.
I can envision that likely out there we will still see somebody wearing those old collaboration things even when they aren't awakened to the very same criteria as fresh cosmetics in buy PSO2 Meseta a similar manner and that there definitely would have been outrage when it was made obsolete or unusable. Collabs who have experienced their cosmetics removed nevertheless have their resources exist on the sport so those will likely still be accessible for jp players.