well, if nothing serious happened after his deal with big mom perhaps he will. i think the new nakama probably a scientist because science and technology is the plot used since fishman island arc. i personally want a fishwoman DF user to join. so, my answer is none of the introduced character so far but, it's up to oda and co anyway.
Im thinking maybe Carrot after Jinbe or at the same time. Also I would like luffy to have a decent size crew. BB had a crew of all insanely strong folks after impel down but still added more. To see all of these veteran crews and fleets be defeated by 10 people would just kind of suck honestly. At least 20 like the Heart Pirates. Although we dont see them in action I'm sure even shanks has a decent size crew.