so I’m a walking part 6 encyclopedia you can ask me anything about eyes of heaven’s plot I’ll probably have an answer. 

Anyway assuming there’s time fuckery in this game, it means this:

jotaro wins > pucci absorbs the green baby > gets heaven stand 

jotaro loses > dio absorbs the green baby > gets heaven stand

Assuming in some timeline jotaro lost, that’s how heaven dio happened.

And this confirms some time fuckery too.