It's not making shit up. Lucas himself can't even keep consistent on what was planned and such as he talked about it throughout the years (Hammil even said once he heard Lucas was aiming for 12 films, not the 9 that is usually said). From the time I spent looking into it a while back, this is what seems to be the case:
-the original trilogy was not envisioned as a trilogy, they had intended to keep immediately going past 6. Once that plan changed, rewrites for 6 went down
-for that matter, the first movie didn't even have the "Episode 4" words attached to the opening crawl, that was added later
-Lucas originally planned that the Force was something that anyone could potentially tap into, just that some could get the hang of it faster and better than others comparing it specifically to yoga
-they had no idea who Yoda meant when he said "there is another". It was included as a tool to use to bring in a new character should Mark Hammil decide to move on from the series. When they realized 6 is where they would be stopping for a while, they settled on Leia
-Anakin and Vader were originally going to have a scene together (presumably a flashback) in 4. Needless to say, that raises an eyebrow
-when making 4, it is highly unlikely they knew the Emperor (who is mentioned once) was a Force user given the many rewrites first with Cos Dashit (that last name, are you fucking serious, Lucas? "Da shit"?) and then the novel implying he was just a political puppet. Also, the script describes Vader as the Dark Lord of the Sith which doesn't make sense since Palpatine is his master
-ROTJ was originally called Revenge of the Jedi. That would imply a very different film and conclusion especially since it contradicts Yoda in 5: "A Jedi uses the Force for knowledge and defense, never for attack."
-Lucas at one point intended for Luke to put on Vader's helmet at the end of 6 and become the new ruler of the Empire
-while Lucas did shoot down killing off Han just because it would hurt toy sales (oh yes, the OT swam in merchandise pandering, lest we forget), he did originally consider having Han die halfway through 6. Makes sense given Han's line of "like I'm not going to see her again" when looking at the Falcon feels random in the final version, like foreshadowing that went nowhere. Harrison Ford and the co-writer of ROTJ were very disappointed that Lucas backed down from this dark twist
-producer Gary Kurtz was "politely kicked off" the production for pointing out that a second Death Star was derivative, but more importantly he revealed that another ending was going to have the Rebels win but with a massive casualty rate that makes no one feel like celebrating, Leia feel unhappy as she becomes queen and must focus on her duties fully, and Luke leaves for parts unknown like a classic spaghetti western
And to put the nail in the coffin, in 1983 Lucas himself said, "there was never a script completed that had the entire story as it exists now. As the stories unfolded, I would take certain ideas and save them. I kept taking out all the good parts, and I just kept telling myself I would make other movies someday."
Also, at ABC's celebration event for the final episode of LOST, the showrunners were given a letter from Lucas congratulating them. Lucas probably assumed the letter would be read privately by them and not out loud at an event, and a reporter was present so needless to say the cat was out of the bad. George Lucas: "Don't tell anyone, but when Star Wars first came out, I didn't know where it was going either. The trick is to pretend you've planned the whole thing out in advance. Throw in some father issues and references to other stories -- let's call them homages -- and you've got a series."
Also, what do you mean, "True the story changes"? So, in other words, it wasn't mapped out, the story is kinda the most important thing in planning out, you know, A STORY? "Well, I didn't know where Luke would be two movies later, but I knew we'd have cute and cool aliens for the kids to buy, so we're all good!"
There's a difference between loving something and putting it on a pedestal, and you're doing the latter. I'm not saying the OT didn't work for the most part in spite of the constant story shifts, but the only ones revising history are those claiming Lucas had all this shit down by the time the first movie hit theaters especially since he himself has said that's not the case.