I’m not so sure that his perception has never changed. There was no mention in the OT of a need for Luke to leave behind his attachments. Obi-Wan cautions him to not let the Emperor use those attachments against him, but that’s not the same thing.
Except there is. Here are quotes from the Empire Strikes Back commentary track:
“It’s pivotal that Luke doesn’t have patience. He doesn’t want to finish his training. He’s being succumbed by his emotional feelings for his friends rather than the practical feelings of “I’ve got to get this job done before I can actually save them. I can’t save them, really.” But he sort of takes the easy route, the arrogant route, the emotional but least practical route, which is to say, “I’m just going to go off and do this without thinking too much.” And the result is that he fails and doesn’t do well for Han Solo or himself.”
-Scene: Luke sensing Han and Leia are in danger
“Luke is making a critical mistake in his life of going after- to try to save his friends when he’s not ready. There’s a lot being taught here about patience and about waiting for the right moment to do whatever you’re going to do.”
-Scene: Luke leaving Dagobah, ignoring Yoda and Ben
“Luke is in the process of going into an extremely dangerous situation out of his compassion— Without the proper training, without the proper thought, without the proper foresight to figure out how he’s gonna get out of it. His impulses are right, but his methodology is wrong.”
-Scene: Luke flying towards Bespin
The Jedi, here, are telling him that he needs to prioritize his training over his attachments. And Lucas agrees with them. Yoda has always been a character used to give his own teachings and philosophy. You read about any scene Yoda’s in and Lucas always portrayed Yoda as in the right.
Also, Lucas was able to give the greenlight on plot points in the EU, so he must have been aware of and greenlit the Luke-Mara Jade romance and marriage and the New Jedi Order doctrine changes. Of course, he later said he disagreed with the idea of Luke getting married, but that was later.
Lucas never liked Mara Jade. Ever.