What you're implying is that over the course of 30 years, while Leia and Luke and Han built a new entire ruling power in the galaxy, they told literally none of their closest, most loyal friends that they were related to eachother? Seriously, why would they keep Chewie in the dark about something like that? Clearly, that's a personal fact, and even if Luke and Leia didn't want the whole Republic to know about it, couldn't they just ask Chewie not to tell anybody? Does Chewie have some "off-screen" history of tweeting Rebellion leader's personal family tree details? And would JJ Abrams and Laurence Kasdan really put that much thought into Leia's political career? You can't actually think that they considered something so un-instrumental to the plot while writing one bad hug scene? This theory is so unlikely that I will literally cut off my arm, eat it, shit it out, put that shit in a box, grind up the box in a blender, put the grindings in a nice savory stew with some cabbage, maybe, and some ground beef, and feed that shit to orphans if any of this is proved true in the next movie. There may also be some tomatoes in the soup, I'm not sure, I haven't decided yet.