New Wildskeeper Reive Key Item

So, having missed the bus (mostly) for doing WR in the first 3 areas, I was fortunate to find myself fighting the big tree Yumcax over in Yorcia Weald. And we won. YAY! I got a neck piece.. woot.

It also dropped a key item, Aged Ligneous Naakual crest. What is this for? And before you say 'Oh, you can open a Delve with that', let me save you the trouble: doesn't appear to be able to... yet. My suspicion is that the next 'tier' of Delve will require one of the new WR KI's, like this one, that cost 75k bayld, to get into. But all of the wikis/forums I've found so far say nothing about this.

Anyone else experienced this? I know, I know - I actually want to get all the KIs in the end, but I gotta work with when I play, etc., so it's tricky. >.<

Anyone else in this boat?

With the previous wildskeepers, clearing just one of them unlocked the ability to get the KI for any of the 3 delve areas, the same is probably true with these 2. There may also be some other purpose for the KIs in the future for all we know, such as clearing all areas giving us access to a wildskeeper final boss.