My biggest gripe:Jill Pill (who I bet will be a pill bug or married to one). I don't mind the S3 story hook, or the fact that she's someone from BoJack's past we didn't know about, but it bugs the ever living shit out of me that she's someone from BoJack's "other TV show" that we never even knew existed. I have a hard time imagining a justifiable reason to hide that from the audience. Just seems like they decided to bolt that onto BoJack's past, was it ever even mentioned in passing?
My guess is
it is going to be a show that bombed so hard that Bojack's huge ego made him block the memories while he clung to the one show that was a success, people around him don't remember because he already is a "has been" and people barely even remember he was in Horsing around, Diane didn't mention it on the book because bojack never told her about it either, it just felt to obscurity.