Right. It's nice to know it's there though, so Waterfox's decision to implement the Brave engine was done with insight from how Firefox itself is implementing it.
Interesting it's there, though. And that it "just works" like a super light version of uBlock Origin. I wonder what they'll do with it. Mozilla is tolerant with ad blocking (but IMO never wants to support it first-party), but they do have several "tracker blockers" they've been independently maintaining for years with similar methods...