Thatll have nothing to do with the crew lol
I know you guys hate Wano. But I have a single counter-argument to all this bullshit:
Franky was willing to die to stop Pluton from falling into the hands of evil. This is a completely underrated part of his character: Franky was willing to die to prevent Pluton's activation, just as Robin was willing to die for the Straw Hats in Water 7.
There is no way Franky would let a guy like Teach get the ship Tom promised him to protect, and Wano/Momo can use Den Den Mushi to announce they're being attacked (Momo can fly to tell them if necessary). If Wano gets attacked, the world will find out about it.
At the least, Franky would move on it, and I doubt Luffy would let him do that alone when he already has issues with Blackbeard, and has so many allies and friends in Wano.
It's entirely possible the Straw Hats move because of Cross Guild instead, though, because I think that's Cross Guild's next move, as Croc and Mihawk want military power, and Wano is full of soldiers, is a natural fortress, and has a ton of weapons leftover from Kaido.
I think Robin would have similar motives to Franky, but, once Wano is invaded, either by Croc or Teach, this will be enough to make the Straw Hats send a force back.
Thus, a reverse Dressrosa, where the Straw Hats land on a new island, then go back to an old one that's in the middle of an attack, rather the end of one; the opposite of Zou.