Yes, they added the words “Episode IV: A New Hope” to the opening crawl in 1980 or 1981 (not sure which, but it was then.) But the movie was still being sold and titled as “Star Wars.” Again, there are formal conventions as to how movies are titled. The crawl isn’t the film’s title.
The (1997, I believe) re-release was the first movie formally titled “Star Wars Episode IV: A New Hope.”
I mean, Lucas just lies non stop about this stuff, I don’t know why anyone would buy what he says; he still maintains with a straight face that Han ALWAYS shot Greedo first and the original version was just “confusing.” It’s his movie, he can change it all he wants. (Well, I guess it’s Disney’s movie now.)