I haven't found much info regarding naturally-aspirated Subaru engines with oil catch cans. Though I do occasionally drive hard, I don't see the need for one with this new short block. From what I could tell on various Subaru boards and forums, the context of various conversations seem to imply they are more crucial on engines with forced induction than naturally-aspirated ones.
Naturally (no pun intended), most Subaru aftermarket oil catch cans are aimed at Subaru's turbocharged performance engines.
Also, I am unaware if oil catch cans are considered "tampering" with emissions equipment. Chances are, if there's excessive oil in the intake system, a check-up on the PCV system may be necessary. If you live in an area with no emissions enforcement, that likely won't be a problem.
"Why would I want to profess my feelings for some 3D girl?" - Tomoya Aki from the anime Saekano