I don't see how Vivi could possibly be useful as a Strawhat at this point. A lot of people say they don't see Kinemon, but it's worth noting that I couldn't possibly give less of a shit about him and have a lot of other characters I'd rather see, and I still think he's going to join. The last chapter is what convinced me.
I feel like we can say the same thing about Kin, except he literally brings nothing new to the table in the crew. Carrot and Yamato at least have unique fighting styles and have open curiosity for adventuring, this we can agree on im sure. The thing about Kinemon is the fact that he's:
- Entirely redundant to Zoro, Brook AND Sanji in many ways (fighting style, personality, etc).
- Has barely shown off his foxfire technique outside of Punk Hazard. Zoro has expressed the desire to learn this technique btw.
- No viable dream or desire to adventure
- Is bound by serving Momo as a retainer
- Has yet to see his wife again but is supposed to leave her after they reuinite?
The idea behind Vivi is her current place in the story. Compare:
- Has had a desire to be a pirate. Still daydreams about it. Is constantly shown hence forth.
- The story is putting her in a situation where Alabasta may be in a crisis. If Im is openly looking for her, then the safest place she could be is with Luffy. 2 SHF members were present at the reverie. So was Sabo. All 3 have Luffys Vivre Card.
- Not only that but her fighting style is actually unique. She doesn't have to be strong, especially not compared to what we have already, but there's no reason to assume she's not stronger than she has been in 2 years.
Imo, Kinemons story ends at Wano (maybe continues as an ally post War.), while Vivi's is now continuing in a very important way. By this point I dont think a role is necessary. Hell, if Yamato joins, his role might not even really be specified. Im at the point where I dont think Carrot needs to be either. It's not like these patterns MUST continue.
Point in case, I dont believe the idea that Kin complimenting Luffy has to mean hes a future strawhat.