Don’t get me wrong, Paradise sounds great, but I think that much of Book 4 invites this interpretation.
First of all, there is the absence of any other explanations. Of course, the devil in disguise appears to be the main source of Adam and Eve’s sin in most readings, but I’d argue that there had to be some fault within them in order to fall for Satan’s lies. It doesn’t seem like this fault can be anger, ambition, jealousy, curiosity, or any of the other virtues that lead to a protagonist’s demise because the couple’s absolute bliss would rule out any of them. Adam and Eve appear uniformly in love and happy, content with their purpose to spread God’s word to their sons and daughters. In their conversation, they relate their current situation and future purpose with a tone that indicates that nothing will ever change and that they are fine with that.