Basically the new Jotaro for the parallel universe.
Cause Jotaro himself made an appearance in parts 3 to 6. And Rohan might do the same in this universe.
honestly, i think you're right, but, i think he will take a role of Joseph from Part 3 of the group, older, wiser leader. Because right now Meryl Mei...she ain leading them on the field....no one is....yet. And I have a feeling an older character like Rohan is the man to be and judging by his apperance and early introduction, I think he's going to tag along.....but also... sadly I think he will die.... but much later. By the Villian....whose stand I still think will be a Nirvana named stand, called Heart Shaped Box (with the power to somehow just take anyones most valued riches/possesions or something, idk into it's heart shaped box....i have no idea how it's ability would work). I'm just thinking, what's the opposite of someone wanting greed....someone wanting to take it all from that person, envy, and hoard it....lock it away.... and Nirvana...only because why hasn't there been a Nirvana named stand yet? I think he's saving it for a villian in this part.
Just posting this so my prediction is on the net somewhere for posterity...b/c I DIDN'T DO IT BEFORE PART 1 CAME OUT AND I PREDICTED DRAGONA 100%. That it was a sibling, maybe a twin, but also, Dragona would be a guy in disguise, possibly stand related (still think that's what it is, and just also enjoys fashion, I don't think Dragona identifies with anything...but Dragona... and doesn't care what you address her/him/them as, as long as you're respectful.)