User blog comment:Xilinoc/Ch. 849 - Boiling Witches and an Ill-Fated Jaguar Husbando/@comment-68.62.209.22-20161208143520/@comment-24850639-20161208150246

I agree. The guy bringing him those ingredients gave that update as if he was asked for it. Sanji was worried about them not doing anything rash last chapter, so to me it makes sense that he'd inquire about what happened to them given what was occuring last time he saw them. I'm sure he's smart enough to know that Big Mom could quite easily go back on her word. Big Mom's people also know what he promised, and about the cuffs.