Did Lucas give any input on the the Thrawn books back in the day? Who got the ball rolling on the idea of novels set post-Jedi? Why didn't it happen until 1991?
The biggest question, one we can't really know the answer to but is still puzzling, is whether GL honestly never intended to make Episode 7 as of '91 and therefore said "sure, do whatever you want, RotJ is the end as far as I'm concerned."