I'll have to question the article's accuracy regarding 'Star Wars', for this reason: In 1977, I was a Junior High school kid in Southern California. We loved everything Star Wars, and absorbed any scrap of information we could get.
There was a cheap magazine (I wish I could remember the title) which stated that Lucas already had the story planned out... and that Darth Vader was put into the suit after a fight with Obi-Wan Kenobi, in which Vader was stabbed with a lightsaber and fell into lava.
If the story arc wasn't planned out at least generally, then that is a wild coincidence.
There was a cheap magazine (I wish I could remember the title) which stated that Lucas already had the story planned out... and that Darth Vader was put into the suit after a fight with Obi-Wan Kenobi, in which Vader was stabbed with a lightsaber and fell into lava.
If the story arc wasn't planned out at least generally, then that is a wild coincidence.