I think Bungie is realizing players want to look how they want to look with no strings attached to it. Granting a perk/ buff for having a full set goes against that IMO, one of the reasons Bungie is removing the XP buff from Iron Banner shaders/ class items and emblems is so players can look how they want to look without missing out on a buff in Iron Banner. Granting a shader/ emote is the most I can see Bungie doing in regards to a bonus.