I just figured nicolo polo took the armor to Italy. Because altiar gave him those keys that ezio searches for in the Middle East. Nicolo said he was going back to Italy for a while. Yeah maybe Niccolo took a look in the Codex before it was stolen, and he redesigned the armour with the help of the brotherhood. They are just there for vanity/cosmetic reasons, and if you don't like the way they look, no one is forcing you to wear them. The in-universe explanation for Legacy outfits is that the Animus/Helix makes it possible to wear the clothes of Assassins from different eras -- in Rogue, they straight up tell the player that Shay can use Arno's weapons because they are "made available through Helix". Im unable to get the Altair outfit in AC2 due to Uplay shutting down and supposedly everything is already unlocked but that does not seem to be the case as Altairs outfit isn’t even in the outfits section in the pause menu. Im on Ps3 if that helps anything and I have the Ezio trilogy with AC Brotherhood, AC2 and AC Revalations on the same disc. ddE5Ay.