As far as the NJO is concerned, had Lucas decided to give the keys of the franchise over to EU authors, I believe Star by Star wouldn’t have killed off Anakin Solo and things would progress from there. The Solo Kids would reunite and lead the charge to retake Coruscant from the Yuuzhan Vong, each sibling goes off on their own path to find their calling (Anakin to become Luke’s successor, Jacen to explore the mysteries of the Force, and Jaina to continue being the “Sword of the Jedi”) and the post-Endor stuff would conclude there. If not, then it would probably focus more on the recovery aspect of the galaxy following the war’s end or Jacen’s journey to learning about the Force while Anakin and Jaina deal with some small crisis back in their galaxy.
I’m guessing the Yuuzhan Vong would’ve been Sith, or the inspiration behind the Sith, and Jacen would’ve been the one to die instead of Anakin, in keeping with the original plans.
https://starwars.fandom.com/wiki/Dark_Horse_invasion_storyline