抱歉，
小弟不察，
一直以來都以為Episode IV是特別版上映時才加上去的。
因為這篇報導：
"With the 1997 special-edition releases of the original trilogy, the first film officially called "Star Wars: Episode IV A New Hope" has totaled $461 million domestically, second to "Titanic" at $601 million. "

我沒有找到1977年上映前的訪問，
不過1999年5月號Premiere有段專訪：

(Page 77)

Premiere：Are you planning to do the final trilogy as well?
To make it a saga of nine films?
GL：No, no.
[After Star Wars came out] somebody asked me if I was going to do a sequel.
And I said, "I'm doing the other two parts to this one."
And they said, "You're doing this trilogy--do you have any more?"
And I said, "I've got a backstory, which I've got laid out. I could probably do that."
And they said, "But are you going to do a sequel?"
And I said, "I guess maybe I could do a sequel at some point."
And that got turned into doing nine films.
Premiere：So it's really six films.
GL：It's six films.
It's really not nine films.
It's extremely unlikely that I will go on and do any more.