I really want the idea of 13 shs, and there'll be 4 sh in nw. However, I think with only few arcs left in the series, I think if therell be new strawhats, they should be present at least in wano, or someone from the past who befriended the sh.
The only people I can think of are:
Yamato - for one, she mentioned she wanted to sail with luffy, she intended to do it and has really great relevance in the arc same how the sh was during their recruitment arcs.
Carrot - dont really see her joining but for the sake of the "possibility" she should be considered. Although, shes completely irrelevant at this point of the arc.
Law - has been with the crew ever since punk hazard, hes been with the crew for the majority of the nw. He has the quirks and somehow bonded with the sh already. He wanted to know the meaning of D which could be a very good point why he'll join. The only problem is his crew, although i dont think bepo and co will object to law's decisions if ever, I mean, theyve been together and they would want law to discover his true self
That's it for those who are currently present in the arc. As for those who arent in the arc. They have to have a deep connection with sh and i can only think of two.
Vivi - because shes an honorary strawhat and obviously wg's target.
Bon clay - do i have any explaining need to do? Arabasta? Impel down?