Did Ursula Le Guin change her thinking about same-sex relationships partway through The Dispossessed?

In Ursula Le Guin’s Hugo- and Nebula-award-winning 1974 novel, The Dispossessed: An Ambiguous Utopia, there are a number of discussions of how same-sex relationships are commonplace on Anarres, and most people have sexual relationships with members of both sexes. At one point, the protagonist Shevek, although he is primarily heterosexual, is happy to be involved in a brief homosexual relationship with one of his friends.

However, earlier in the book, before the same-sex relationships on Anarres are ever mentioned, there is an odd passage in which Shevek is talking about the culture of his homeworld with one of his hosts on the sister planet, Urras.

“Is it true, Dr. Shevek, that women in your society are treated exactly like men?”

“That would be a waste of good equipment,” said Shevek with a laugh, and then a second laugh as the full ridiculousness of the idea grew upon him.

The doctor hesitated, evidently picking his way around one of the obstacles in his mind, then looked flustered, and said, “Oh, no, I didn’t mean sexually—obviously you—they. . . I meant in the matter of their social status.”

With Shevek’s joke about “a waste of good equipment,” it certainly sounds like he means that homosexual sex is a waste of the reproductive organs. Yet this seems quite at odds with the attitude on his home planet that is described later in the book.

So, is the reason for the inconsistency known? Did Le Guin originally not intend to have same-sex relationships as a part of the Anarresti culture, only changing her mind when she had written more of the book? Or is there some other subtlety that I am missing?