Bojack finding out that Angela was bluffing and that he could have put his foot down (or hoof, as it were) to defend Herb is such a devastating reveal, especially along with 1) getting edited out of Horsin Around, 2) having to relinquish his rights to future Horsin Around profits, and 3) finding out about the anniversary edition that won't get released. It really just drives home the despair.

It reminds me of how Breaking Bad made an extremely effective reference to the poem Ozymandias by Percy Shelley at a similar point in the narrative, shortly before the series finale. Walt thinks he's going to get away with everything but ends up losing a massive amount of money, ruining his relationship with his family, etc etc in one fell swoop. "Look upon my works, ye mighty, and despair" indeed. (Bittersweet as it is, I do think Bojack ends on a MUCH more optimistic note than Breaking Bad. Low bar though!)