I'm just theorizing based on possible foreshadowing and how shonens work.
I knew it would be an unpopular opinion and it's way out there right now.. but it could be made to work. Shakky and Rayleigh are upper tier revolutionaries so there could be more to that conversation than something that jumps out and states it blatantly. Plus the Luffy / Boa relationship has been fairly heavily built upon.. and if Luffy did find a woman, since he is deadly serious with friendship when it came to love he's not just gonna pull a Sanji when he sees a nice set.. and they really are great for eachother if she warms up and she can protect his progeny better than anyone else that was revealed. Boa would have to change alot, but that type of thing isn't alien in this type of story.. plus Boa was one of the first characters conceptualized for the story for Oda.
And this was stated…...............where, exactly?