The Black Armoury Expansion was so bad to play at the start that...
I basically played more PvP than PvE or anything, and just avoided/forgot the expansion's content.
Seriously, I have been playing Crucible more than anything.
Every day I play Destiny 2, it is always the Crucible.
Sometimes the only thing I play is the Crucible.
I kinda progressed in the expansion where you have to kill fallen on Nesses, but I was so lazy, bored, and already felt alienated by the expansion, that I forgot about it.
That's just my experience, and I am not enforcing my opinion on anyone.
That's all!