That probably might be the case and that would really suck for me personally cause I really wanted Vivi to the join crew after Crocodile was defeated? Know what I mean? Did you hate that feeling when you realized that Vivi wasn't going to stay with the straw hats?She's a character who I just can't see die at this point of the series. There is possibilities that the button doesn't work for some reason or that someone stops her.
I think Kinemon is a strawhat material, but we haven't really seen much of him, the same as his son and Monet. There might be some arcs before they reach the Wano country, so Kinemon getting attached to the crew is a big chance. To be honest, I think he'll do the same as Vivi.