That would be when he met Whitebeard, who saved his Island and showed him that there are good humans in the world, and it was also enhanced by his time spent with him and his crew. It caused him to evaluate his actions and morality. His change then culminated on his meeting with Luffy, both directly and indirectly (When Luffy took out Arlong).
And I don't think Merry and Kaya will be in the next cover.
614.First was the Introduction. The article about the return of the Straw Hats in the newspaper.
615.Fuusha Village - Luffy's First Hometown
616.Mt Colbo - Luffy's Second Hometown
617.Shell's Town - Where he met Zoro (And kinda met Coby)
618.Shimotsuki Village - Zoro's Hometown (kinda)
619.Orange Island - Where he met Nami (And Buggy xd)
620.Rare Animal Island
621.Syrup Village - Where he met Usopp, Usopp's Hometown.
Predictions:
622. Baratie - Sanji's Home Ship xd
623. Commi Island - Nami's Hometown
624. Dawn Island (probably will show the shop where Zoro bought his katanas, before they were destroyed)
625. Reverse Mountain - Crocus and Laboon place
626. Whiskey Peak? I guess it will show some old Baroque workers and their new lives?
627. Little Garden - The giants? Or maybe it will show Elbaf, or them going to Elbaf. I don't think so, though.
628. Drum Kingdom - Chopper's Hometown - Dalton and Dr.Kureha probably
629. Alabasta - How's Vivi doing (Maybe they'll make one cover for Yuba, Toto and Kohza, and for the Palace, Igaram, Cobra and Vivi. I don't know. Let's say it will onl make one of the palace, or something with Vivi)
630. Jaya - How are Cricket and the Monkey Brothers Doing.
631. Skypea - How are the Skypeans and the Shandians doing
632. Long Ring Long Island - How's Tonjit and Sherry. He's probably on another "situation"...
633. Either the Sea Station, with Kokoro, Chimney and Gonbe, or Water 7 with All of them, Franky Family, Iceburg, Paulie, etc etc. Probably the later.
634. I'm not sure. Will he show Thriller Bark or Brook's old ship? There's no one there, other than the grave of Brook's mates. But then again, I'd be satisfied with only a grave. Maybe we will see how's Lola and the Old sick man that looks like a zombie.
635. We already saw the reaction at Sabaody Archipelago and at Women Island, so I guess Impel Down, where he will show Mangellan and Bon Kurei.
636+. I think now he will stop showing places where Luffy went, and show places where people that matter to Luffy, or that he had an impact on. Probably Shanks and the Red Hair Pirates. Marco and the Whitebeard Pirates. Buggy, Alvida and Mr.3. Maybe the Supernovas. And finally, Blackbeard
