It's not so much about stuff fitting together as it is about acknowledging "yes, this stuff you loved still happened." They don't have to bring up anything that's happened in the 35+ years since RotJ (in fact, I hope they don't), but the new movie can't make any blatant contradictions like Chewie being alive and still be in the same universe as the "old" EU. It's either one or the other.

Look, I don't mind minor inconsistencies. Star Wars is only slightly older now than Trek was when Enterprise started, and I can still remember being distracted when they played a clip of Zefram Cochrane from after he'd already left for Alpha Centauri.