Imagine for example you were reading Part 2 in the late 80s, and suddenly Wham and ACDC decide to put what they literally call 'wedding rings' in Joseph, being that manga published not only in a time where same-sex marriages were forbidden in most places of the world, but also in a country in which homosexuality was seen as some sort of perversion. There is a lot of subtext in JoJo about different queer themes, but there are also others that are mistakenly seen as gay but are not, and in order to analyze its relevance we should understand the context in which the manga was published. TL, DR: JoJo is not gay or straight, it just represents freedom
In my opinion, it is not as simple as answering a 'yes' or 'not'.
