Idea: After things go wrong in the future, Luke and his son Ben go back to the past to save and possibly recruit Grand Admiral Thrawn.
Luke and Ben Skywalker's reason for being in the past would be to change the future since they come from an AU where Jaina failed and Darth Caedus survives, Allana and her mother dead, Han and Leia on the run, Jagged Fel and Zekk mourning the loss of Jaina and swearing revenge, Zekk once more turning to the Dark Side, survivors of the virus meant for Fett battling with Caedus' forces, Jedi Order scattered some of them oddly enough aiding the Mandalorians in their cause under the leadership of Bardan and Kad, etc. Reason Luke chooses Thrawn Trilogy era is that during meditation on the subject he finds both Thrawn and that time to be a turning point for the galaxy. Thrawn's survival would be a great asset during the Vong invasion that comes 15-16 years later since he had been preparing for decades and had managed to defeat a scouting party. With the changes, it is possible that Chewbacca and Anakin Solo would survive, preventing the major cause of Jacen's turning into Darth Caedus. Maybe have Luke mention the remains of the Chiss he'd found next to those of Knight Lorana Jinzler aboard Outbound Flight.
While Captain Pellaeon thought that the way that the ship which had seemingly appeared out of nowhere had buzzed the bridge and left without attempting any further harm was both extremely frightening and rather odd - mostly frightening - he didn't understand why it caused quite the reaction it did in both the young Navigator and the Admiral standing next to him. Ensign Wellwith was standing there gaping like some sort of large mouthed fish and the normally stoic Grand Admiral Thrawn who didn't duck like the rest of the bridge crew when the ship had come within inches of striking the hull had just spat a mouthful of Caf all over the bridge windows and looked like he was choking.
"What did I miss?" he asked the galaxy at large.
"S-Skywalker Maneuver...in a freighter." the Navigator stammered.
Gilad Pellaeon felt like sitting down. The nearly impossible Skywalker Maneuver that he'd never personally witnessed until now had been something of a legend amongst pilots since the Clone Wars, and was meant to be done in a one man craft such as an Aethersprite or a certain TIE Interceptor that he'd heard had scared the shit out of the bridge crew of the Executor on a couple of occasions until they had gotten used to it, not a freighter, and most definitely not a freighter that was planning to buzz a bridge with a group of Yalsmari, considering the extra factor that was necessary for a pilot who wasn't truely suicidal to pull that maneuver off successfully.
"Insert Scene where Luke from the future {after Invincible AU naturally} visits Thrawn. Pellaeon wonders why the Admiral immediately believes his story and have Thrawn explain that Luke had conclusively established his identity before boarding both by successfully pulling off the Skywalker Maneuver in a freighter, and by the freighter itself which was a logical next step in a current design, and based on its used appearance could have only come from the future. Have Thrawn further explain that parts of his story are known to very few people and that they have been long sworn to secrecy.