I didn't get the impression that Ember fully killed recognition- mostly because Mender and Leetah were needed to really put an end to it. I thought she just kind of shoved it to the side temporarily.
Tavie said: Careful, don't let Elfmom see you talking this way...If Elfmom didn't want to open that can of worms- she shouldn't have labeled them cousins. I fully agree that analyzing the interconnections is sort of silly- but the elves are apparently aware of them, or Cutter wouldn't call Dewshine his cousin, and Ember wouldn't tell Tier he was hers. Hey- that only makes sense. Plus, someone asked- and the way it worked out was pretty simple and clear.