So I'm curious, with all the focus on BB (who knows how tied he is to this Vegapunk arc), it really does feel like he'll be the next Yonko down and not Shanks. I assume the 4th RP was hidden somewhere and that's what Luffy and Blackbeard fight over, the right to go to Laugh Tale and be PK.
The real question is how Shanks fits into this considering his goals.