That panel where BB says: "I won't let that fall in the WG's hands, i'll take it for me." (Or something like that.) I think hes talking about the Mera mera no Mi.
In my conception this is one of the reasons he won't be coming to wano you know, he's always been a coward. I don't think he would show up unless he knew Kaido and Big Mom are defeated or something like that.