Tashigi, Perona, Koby, Moria all on Hachinosu island, Pudding with potentially Law coming soon escorted by Blackbeard...
I'm pretty certain that SWORD is about to get its teeth kicked in? There's no narrative weight to the Blackbeard pirates losing. But it's also unlikely Shiryu will be the one to take Garp down, again that makes no sense in the context of the story. Shiryu and Luffy will never share panel time together.
I'm guessing Garp is going to flex on the Titanic Captains and Teach is going to arrive to salvage the day and kill Garp. Then you have a loaded cast for whenever the Strawhats take on Blackbeard.