Oh please don't be like dragonball and start bringing people back from the dead.
I no longer trust Oda, it took him a decade when he started the show and all that the season has to show was ace dying and whitebeard saying that one piece is real… nothing was answered, none of the other character's main motive was even acknowledge. It took almost or a whole decade just to show 20% progress in all of the character's objective. I wouldn't be surprise when I turn 90 and on my death bed only to realize that the straw hat is still half way to their goal of the line.
To be honest I think Oda is trying to milk it or he's out of idea and starting all over again.
If you only realize, you should understand that TOEI is making this fillers in order to not catch on the manga, which i why they will insert as much applied fillers as possible.
And have trust on Oda. He already planned out the ending of One Piece, so I don't think he is going to milk down the story that much. And it's impossible for him to ran out of idea. There are just too many potential plots that can happen.
And I really like the Marineford arcs. There are just a lot of things that can happen from it. Like, what will be Moria's future? What will Crocodile and Mr.1 do now that they have decided to go to the New World? Why did Law save Luffy? What will happen to Whitebeard Pirates from now on? The islands they protected? How powerful is Blackbeard after the war? How will Luffy even defeat him?