Part of the One Piece is in Wano

[SSJ2]

When Big Mom is beaten and is talking about the One Piece, she says that part of it is in Wano and that she was so close to it. Is this in reference to Pluton? Maybe the ancient weapons are needed to use the One Piece?

 

[Warmmedown]

This makes it seem like she's just asking if Wano has some of the answers and doesn't know. Maybe she's just saying it because Oden helped Roger find Raftel. It could foreshadow or be a red herring. It could be Pluton. Maybe Pluton can be used to find One Piece. Maybe the knowledge of how to decipher the poneglyphs is still on Wano, in a book or maybe in the mind of Mononosuke.

 

[Yoshi]

Yeah, it could very well just be connected to the One Piece.

 

[Future Warrior]

This may have meant Pluton. And from what I can remember from Vegapunk's speech, finding the One Piece leads to gaining control of the ancient weapons.