You see. We really don't know that is Luke. It could be Luuke from The Last Command novel.
Luuke Skywalker was a genetic clone of the Jedi Knight Luke Skywalker, grown from cells extracted from the hand Skywalker lost during his duel with the Dark Lord Darth Vader on Cloud City. Skywalker's hand and lightsaber were recovered by Vader and taken to Emperor Palpatine's Mount Tantiss storehouse on the planet Wayland. In 9 ABY, the insane clone Jedi Master Joruus C'baoth performed a mind trick on Imperial Grand Admiral Thrawn's subordinate, Captain Gilad Pellaeon, ordering him to make a special clone for him. The clone that later became Luuke Skywalker was grown in secret from sample B-2332-54, the sorting code assigned to Luke Skywalker's hand. The clone was grown in a Spaarti cloning cylinder over the period of less than a month. When he was ready, the clone was given Jedi training by C'baoth and over time became little more than an extension of C'baoth's will.
