Rise of Iron has always been met with reticence by the current writers it seems. There was that concept art for Nessus and the exodus black relating to Siva that never went anywhere. And then RoI was practically treated as non-canon. We’ll never know, I suppose. Personally I kinda liked the somber mood of RoI tbh. It fit better in tone with a civilization fighting for its very existence. The cartoony witness, Nimbus’ high-fiving Caiatl’s loss of her father, the overdoing of Cayde’s comedy (a character with such a tragic background), turning crow from original rogue concept to -blam!- prince to cringe guardian … and so on … quite a few moments in destiny just felt off. Burying … or “tying a bow on” RoI was a missed opportunity imo. Edit: Cayde-6 is still one of my favourite destiny characters, Nathan Fillion did a wonderful job. The writing for the character just sometimes went too far into dumb joke territory, beyond just a coping mechanism for Cayde.