Back in the 80s and early 90s, fanzines and game boards got shut down for homosexual content related to SW, even just discussions. It hasn’t made a huge splash because fandom has eased up A LOT since then, but it was a legitimate thing that Bioware flat out described homosexuality as not existing in the GFFA in their game worlds. I’m sure Lucas’s position has evolved on it the same way everybody else’s has in the past thirty years.
Yeah, I suspect there’s at least some homophobia there, if nothing else the lack of it in the prequels and just the general age of the guy are things that would lean me in that direction. And the truth is that LucasFilm did get after people for gay content in their fanzines! And that George could have stepped in to say, hey, it’s fine, let them do what they want.
But without reliable sources to tell us the actual details of how much George was or wasn’t involved (especially knowing his tendency to not get involved with even the commercial versions of the extended universe of his series!), I’m not really willing to speculate. (This fanlore article has a lot of the details, including the actual letters, for that whole thing!)
I feel like the problems with George Lucas are generally more in his lack of awareness on things, rather than outright hostility towards them. A lot of the more potentially fraught issues of his movies (the complicated use of Eastern cultural elements, the lack of more people of color in primary roles, the lack of textually queer relationships, etc.) seem to be of the sort that aren’t directly awful, but may show a lack of understanding.
But also that we’re dealing with something 35 years ago by this point and, yeah, it’s not an excuse but sometimes it is an explanation. And fandom was a different place, just as society was a different place back then. It doesn’t mean we should forget these things, but also let’s provide actual sources when we can. (I’d certainly be curious to know if he’s evolved over time and what his Star Wars would have looked like on a detail level!)