I think the film might go even further with its message. By the end, Tar is still brilliant and nobody can take that away from her. She will most likely rise to the top again but perhaps only in this niche fandom. It shows that even after the cancellation of someone they're still living. They don't cease to exist, no matter how much people want them to.
She falls from grace but she does land somewhere with a certain amount of power intact but on a much smaller stage. The message could be falling on the side of the old argument of "separating the art from the artist." Or TAR from the TARtist. Roman Polanski still does great work. Kanye still does great music. Louis CK is still hilarious.
They live on and keep creating great things. Nothing can change that. It just comes down to how comfortable people are with admitting it.