It goes by product type. So being that there are 4 products with Citi AA Gold, Platinum, Executive and Business for bonus purposes, here is your case:
Citi AA Executive is a whole different product from Platinum and Gold Citi AA credit cards. So if you have never had a Citi AA Executive, you will receive the signing bonus if you are approved.
Correct, having a Citi AA Gold World Elite card will not prevent you from getting the signing bonus if you get approved for the Citi AA Executive World Elite Card.