Allow players the ability to potentially obtain past season activity shaders (Crucible, Vanguard, Gambit, Iron Banner, etc...) from armor drops, loot chests, or activity related engrams.
While not much, adding the slight chance or recieving these old cisnetic shaders would help motivate players to play these activities aside from weekly ritual rewards.
We know the capacity for this type of feature exists with the low chance to unlock the Gambit Jadestone shader by playing Gambit so why not do this with other activities and shaders?
Most of the older activity shaders aren't like ornaments that need to be earned or unlocked (to my knowledge at least) so why not give everyone the chance to have them?