User blog comment:Carabe197/Two questions/@comment-1447397-20131027071347

Araki said that Rohan will nor be in Part 8 as for Polnareff and Diavolo probably not they just seem unlikely since they arent from part 4 also Koichi doesnt have a SBR counterpart. It is also possible Diego had sex with some women and left just like Dio but it wouldnt be Diegos son that appeared since that was like 200 years before Part 8.