-Ashfur goes to the Dark Forest for his role in Hawkfrost's attempt on Firestar's life and his attempt to let Jayfeather, Lionblaze, and Hollyleaf burn to punish Squirrelflight for choosing to be with Brambleclaw rather than him.
-The Dark Forest literally shuns Thistleclaw for his actions in regards to Spottedleaf. Not even they want to associate with someone like that. And yes, they do make sure everyone knows about Thistle's actions, even those who lived after he died and the trainees.
-On a similar note; Dustpelt doesn't try to date Fernpaw/cloud. She was an apprentice when he was a young warrior in the first arc.