I think it’s just because he’s not family. It was an industry event, and she knows him through the industry. I don’t remember if they ever mentioned if any of the other main characters were at her actual wedding. I just imagined that her private wedding was family and pre-hollywoo friends only. Especially for Judah, because I don’t think he had nearly as many Hollywoo friends as PC, and he wasn’t even at the industry wedding.

Cuddlywhiskers and Bojack were discussing asking her to be on his show during a trippy “flashback” during their bender. The flashback of Bojack really talking to Sarah Lynn, when she says the light inside her is dying, actually happens in the next episode, totally separate from the context of the bender. You see that after she dies. It’s just what happened shortly after the flashback during That’s Too Much, Man.

He says himself at the AA meeting with Sarah Lynn that he tried to sleep with her.

No idea who that lady is……