Another test for misogynism is the no-win situation for women: if they have sex, they are sluts, but if they don't, they are prudes. Again, I don't see that in Anthony's books. His men aren't constantly putting women into no-win situations. I don't see slut shaming. I don't see verbal violence. I don't see any sort of trollish behavior at all.
If I was a woman-hating man, would I get any satisfaction from these books? I don't think so. So failure to appeal to the misogynistic audience strongly indicates that the books are not misogynistic.
As I've just reread Anthony's early Xanth books, I find that the women there are depicted and referred to in a highly stylistic, somewhat demeening way, very reminiscent of the way that a pinup girl from the 40's or 50's might be depicted. His humor reminded me of the type of gender humor that you would get in radio shows. When I checked up on Anthony's age, the result confirmed my observation. He was born in the thirties, then became a teenage in the late 40's through the 50's. In other words, his depiction of women is consistant with the male narrative of women that dominated the United States in the mid-century.
There's a word for the male attitude towards women in the mid-century. That word is "sexist." It is this very narrative of sexism that led to feminism and bra-burning. The male culture provided a narrative of what women were interested in, assigned to them the traits of illogic and nonsense, and the idea that a man loves a woman but you basically have to put up with her as well. Finally, the ultimate purpose of a woman is to be there an available to a man, and to make herself available as well. That's the narrative that I see in these books as well. In fact, the story for the Source of Magic begins with three henpecked husbands, which is a comedic trope that died upon meeting feminism. That very comedic trope only woeks in the context of sexism.
Are any of Anthony's other books misogynistic? I can't answer that question. I don't feel that the Incarnation of Immortality are misogynistic. I've not read Bio of a Space Tyrant, but from the title, I would conclude that the space tyrant is more kinds of -ISTIC than misogynistic. That comes with being a tyrant. I have some vague recollections of the Split Infinity series, which jibes with the Incarnations series.
So my opinion, for the record, is that Piers Anthony writes sexist books, but not misogynistic books. I can't definitively say whether his sexism transformed or softened over the years, but my opinion is that he did become more inclusive as the years went by, lessening the sexism as he learned that he had a wider audience.