The new member is former shichibukai ...

Just read the new chapter of OP and I think I know who the next member to join will be. Former shichibukai Bartholomew Kuma I mean everybody wants Jinbei to join so why cant he. Sentoumaru said his behaior was irregular and we can see that Shakky is okay. So I think that he will show up and join them (whitebeard's allies prob wont like this too much) or do like Robin did and appear on their ship. If he was to join the crew would be incredible.