Emet-Selch and/or Edlibus already made earlier comments that made it quite clear that the Warrior of Light has a split up Ascian's soul, one that is dear to Emet-Selch. So that was no relevation from after killing all the lightwardens, it was telegraphed long ahead. And i didn't get the impression that the WoW is now "complete", they are just more complete than before, complete enough to not succumb to the light. Hydaelyn being a primal wasn't a bombshell either in the game, it was a (potential, some people also figured it out before due to Ifrit's comments) bombshell in the trailer where it was revealed.
Nevertheless, this is all interesting for the overarching story, the knowledge we gained will lead to interesting developments, but that's what i already said in my first post. The expansion's story is very interesting for the greater storyline, but just taken for itself, the stuff that makes up the actual story of this expansion, saving the first by killing the lightwarden, is pretty bland and boring when compared to HW and SB.