[Matrixbeast]

Concerning the very imminent threat that is the cluster, I think S3 will mostly be focused on that, and seeing as how we have a new addition, I anticipate we'll be getting more history on Peridot than the others.
Not saying that we won't get a little more on Pearl, but I highly doubt we'll "Explore" Pearl's history any time soon.

Lion's mystery is a part of his character, so I fully anticipate not learning a damn thing about him until endgame.