Yah, for me too in the first few chapters, but I'd sortakinda gotten used to it by the time I got to the bit I quoted (it may have helped that this was a reread -- I first read the book many years ago). Since the five sexes and people talking about them (and on culture treating all five as being perfectly ordinary but all distinct) are kind of important throughout the story, the pronouns were needed, and I suppose Scott probably figured they had to be as short as the pronouns we use today and fit the familiar pattern. I don't know whether she expected her audience to start hearing the pronunciation in our heads from the old letters, or just wanted a merely visual "this is a pronoun but one of the non-20th-Century ones" tag.
(no subject)