Actual Oda quotes:
Whitebeard didn't say finding the One Piece starts the war, he said someone will challenge the world, there will be a great war, and finding the One Piece will stir shit in that order. His final words could literally mean someone will fight the world in a great war for the One Piece and will turn it upside down when they find it.
Roger's "too early" quote could mean a lot of things, and it's very likely something like the destroying the Red Line theory rather than confronting the World Government.
Oda: "I’ve always pictured what the final chapter of ‘ONE PIECE’ would be like, though from time to time, the situation surrounding it changes. It will still be over whenever the One Piece is found in the series, haha. Anyway, this next arc is the final one."
Oda: "Okay. It’s not so much that I’m “quitting” as that the series will end when I’ve finished drawing the most exciting part of Luffy’s adventures, which is the big story of what the One Piece is. But right now we’re in a really exciting story in the land of Wano, but if Luffy manages to survive and sail away, I’ll be drawing major international developments, the “biggest battle in One Piece history,” which will be a thrilling and wild story the likes of which no one’s read before. It’ll be great!! So I put out a statement indicating that this very long story is actually moving toward an ending, so that you readers can mentally prepare yourselves. But for now, we’re in Wano and it’s really heating up, so sit back and enjoy it. I’ll draw with all of my strength!!"
Whitebeard didn't say finding the One Piece starts the war, he said someone will challenge the world, there will be a great war, and finding the One Piece will stir shit in that order. His final words could literally mean someone will fight the world in a great war for the One Piece and will turn it upside down when they find it.
Roger's "too early" quote could mean a lot of things, and it's very likely something like the destroying the Red Line theory rather than confronting the World Government.