Exactly, I feel like this discussion is moot until Wano is actually done. If nothing truly happens soon, then sure it was never meant to be. However just the prime fact that he has kept her around with Nami instead of with Inu like she was in the first half of the arc, is interesting to say the least.
Its sort of my mentality for both Carrot and Yamato. I believe there can and possibly will be opportunities to explore their motivations/backgrounds/etc, but we have to also realize Oda is playing a massive balancing Act with like 40 other major characters this arc. If or when Carrot/Yamato get their moments, it will be a point when Oda needs it to be important to drive the story.
Technically, Carrot has had more to do on Onigashima than Chopper or Usopp as of yet. I personally think Oda is, like many people are thinking, keeping her around to drive an eventual point of relevancy. Possibly this will happen through Perospero or this may happen eventually by some other aspect. She is NOT with the Minks transforming or avenging her country against Jack. Its weird.
Yamato is sort of in a similar boat but even more so due to actual relevancy in the plot currently. He has already proclaimed his allegiance to Luffy, has pretty major ties to a past character, hints at a major flashback, is currently serving a function in the plot (taking care of Momo/Shinobu).
In the end, the point I'm making is that Wano has so much to cover, that it takes weeks or months to even truly realize a full plot point being made. Hawkins was gone for 35 chapters, nearly a full year. It took Apoo 40 chapters to be introduced in the arc, and another 30 to do something relevant. Law hasn't even done much in the last 7-8 chapters. Neither has Kid. There's only so much Oda can draw in a 15-17 page chapter with irregular breaks.