Star Wars: Why George Lucas Replaced Anakin Skywalker's Force Ghost

screenrant.com:

Here's why George Lucas changed Anakin Skywalker's Force ghost from Sebastian Shaw to Hayden Christensen in Return of the Jedi. Lucas has made many changes to the original Star Wars trilogy over the years, with mixed results. Hayden Christensen's cameo as Anakin's Force ghost during the Rebels' celebration on Endor is one of the more controversial Star Wars special edition alterations, and it's pertinent to ask why Anakin's Force Ghost is young, as well as what this implies in terms of how Jedi Force Ghosts work.

In both Return of the Jedi’s 1983 theatrical cut and the 1997 special edition, Sebastian Shaw's version of Anakin's Force Ghost is seen accompanying Obi-Wan and Yoda, watching over Luke as he reflects on his journey. The implication is that Luke is seeing his father and mentors as he remembered them. Indeed, when Luke finally met Anakin, Anakin was an older man.

Related: ROTJ's Vader vs Luke Duel Perfectly Flipped Anakin Killing Dooku

For the 2004 DVD release of the original Star Wars trilogy, Lucas changed Return of the Jedi's ending so that instead of Shaw, Anakin’s Force Ghost was played by Hayden Christensen. The move drew angered audiences, particularly since the DVD set came out during the height of prequel backlash and criticisms against Christensen's performance in Attack of the Clones. For many, this was an unnecessary change. However, here is Lucas' explanation for why Anakin's Force Ghost is young, as well as how it affects the future of Hayden Christensen's Darth Vader.

In an event where George Lucas and Hayden Christensen interviewed each other and answered fan queries, Lucas explained that the reason why Anakin's Force Ghost is young is that he metaphorically died after becoming Vader. When Anakin