The official view is:
No FAQ Required: This is not a rules FAQ for any Pathfinder RPG product, but rather a question about our publishing practices on pick-ups. When a new book comes out in the RPG line, chances are at this point that there have been Player Companions, Campaign Settings, or other products on a related topic at some time in the past, but these products have smaller print runs than RPG line products. At product launch meetings, staff members including the developers of these previous products suggest other books to reference for pick-ups. A pick-up essentially means that a rules element begs for a broader audience, rather than asking a freelancer to produce something new but almost identical without regard to the essential foundation built from the design and development work on the previous lines. That said, a pick-up is not a reprint: those pick-ups receive multiple additional development passes just like the new material for the book, refining them beyond their original version. Sometimes these development passes won’t yield any change, and sometimes they lead to substantial changes.
The fully refined version will be Paizo's default version for adventures, NPC compilations, and the like moving forward, since it benefited from two development cycles and is available on the PRD, but as always feel free to use the version that your group prefers, or make your own variant. In Pathfinder Society, always check the Additional Resources page to see what versions are legal and the Campaign Clarifications page for the Pathfinder Society team’s updates on how to use those options in the Pathfinder Society campaign.
You also have stuff like Lore Warden and Pact Wizard which also have two versions, even on AoN.
In this case (pouncing fury), it looks like there was only a minor change, so it seems like you should use the later version.