Found the TWAB that mentions it: https://www.bungie.net/en/News/Article/50350 [quote]With players now able to turn their armor into universal ornaments, we’d like to clarify how and why some armor doesn’t appear unlocked in the Armor Customization area. - Armor won’t show up if a player is wearing that armor. - Some armor sets were purposely combined into one set to reduce players accidentally overspending their tokens for duplicate armor. Examples include: — Gambit Prime Armors – Anyone who unlocked a Gambit Prime armor set has access to the Illicit (Basic) Gambit Prime Armor Synthesis universal ornaments. — Leviathan Prestige Class Items – The Prestige class items from the Leviathan raid uses the same arrangement as the base version, but uses a different dye to distinguish the two, so we reduced these two items into one item for Armor Synthesis. — Red War Parade Armors – The Legendary sets share appearances with the armor from the Red War introductory mission. — Green and Blue Solstice Armor – The appearances of these armors are identical without support of the Glows and were reduced to a single set. The green set also matches the wrecked parade armor, so it was reduced further. — Purple Solstice Armor – As we announced last week, glows from 2018's and 2019's Solstice of Heroes are being worked on and will be implemented later this year for the Legendary armors only. — Exotic Armor – Exotic armor cannot take the appearance of alternate armor, nor can Exotic armor be converted into a Universal Ornament and used on Legendary armor. — Year 1 Armor Ornaments – These are being worked on and will be implemented later this year. [/quote]