About the Mount Reliance boss (Patch 9.8 spoilers)

Are the writers just confident enough that the player base has forgotten about the Deep Kingdom story arc they abruptly abandoned during Oceanheart, that they're willing to reuse old plot points from it now? It's practically the same as the last time we fought Duke Radenkov.

I guess it's too much to ask that they establish consistent rules for how time travel works in their setting.