I highly doubt it will rear it's head in 2.3 let alone show up at all.

I mean what would be the point of the system anyways? Nobody would bother capturing them asides perhaps for posterity. Nothing exists that would make having a primal in your pocket to summon. Considering it was supposed to change the world's weather and all sorts if potentially cool stuff... I just don't see it until they do something big with the open world. The idea was likely shelved in preparation for the dungeon treadmill.

The only way I see this coming back is either hilariously useless or part of a larger expansion pack that focuses on fleshing out the open world. It just can't fit with the current state of the game's design.

That's my bet anyways.