I can't say, I had a great revelation at the time that I reread Gatsby, though I did mark the way Gatsby has to erase his past, which includes Mr. Gatz, his father, who shows up at the end of the book (rather like Josiah Bounderby's mother who reveals that his own life story is largely is his own creation in Hard Times).
Now I have a somewhat different perspective on it, after having read Susan Cain's Quiet: The Power of Introverts in a World That Can't Stop Talking. Jay Gatsby who worked his way up assiduously through careful planning and delaying self-gratification exemplifies the profile of an introvert. He remains invisible at the huge parties he hosts, only relates to one person at a time, attempts to create a new persona for himself, and never quite feels at ease in the social circles he attempts to penetrate. Tom exemplifies the extrovert, supremely confident and outgoing -- so much so that he shows off his mistress to his wife's cousin. In contrast, Gatsby has remained constant to his love for Daisy even years after her marriage to Tom.
The fact that Gatsby still feels connected to Daisy is not a reflection of their deep, spiritual connection, as is the case of Catherine and Heathcliff, but of the introvert's tendencies to form deeper attachments to fewer people. He has latched on to Daisy and then latches on to Nick, the only character in the book who has the ability to appreciate Gatsby for all he is and tries to be. In Wuthering Heights, Catherine's daughter is the one who has that ability and who can assure a brighter future for the next generation, which redeems the sins of the previous one.Thus Bronte's vision proves more optimistic --despite the haunting gloom it is associated with -- than Fitgerald's vision.
Related post: http://uncommoncontent.blogspot.com/2012/04/working-alone.html