@Nilitch:
So what, Bigmom will warn Luffy before trying to attack the Baratie so that they can protect him ?
When Cracker will be in EastBlue nearby the Baratie, Luffy won't have time to move his ass there. Also it's not only about Zeff, but every relatives they have just like Pekoms said.
It could be Dadan, Iceberg or Vivi.
And now they're heading for Wano. They're moving forward as if Bigmom's threat against their relatives had never existed.
The thing is that we can't repeat the same pattern that we did with the Buster Call and Robin. Because with the buster call it only concerned the SHs and Luffy said "We'll get through that issue". He can't say the same thing because Zeff isn't sailing with them on the Sunny.
In the end, the problem of this arc (Bigmom threatening Sanji's relatives) hasn't been solved by the end of the arc. They just went there, fought people, and left. Why did WholeCakeIsland even happen ? All Sanji had to say was "no, fuck you Bege. I'll let Nekomamushi screw your face now, bye. We'll figure out how to protect our relatives, we're not repeating EnniesLobby again. nope."
…Except he didn't have that mindset in Zou. Hence the character development.
The Big Mom Pirates aren't going to be likely to attack Baratie after this, and I'm pretty sure Sanji is aware of that. Most of the threats were made by Germa who are now allies/neutral. The threats were made to get Sanji to come to the wedding, which he did, and the fallout that ensued was not centered around him - indeed, in her brief screentime after eating the cake, Big Mom's entire focus has been on Luffy.
But if, for whatever reason, Big Mom targets Baratie, then the Straw Hats will respond no matter how much of a head start the BMPs have, and Sanji will be glad to have his crew behind him in this. They don't micromanage their allies, and that may have negative consequences at some point, but they will always come when they are needed and they will fight to the end.