I think it’ll be the finally nail in the coffin of the British Left...sad to see
It did look as though Starmer was looking for a way to get rid of her. An actress writes an article that contains an unsubstantiated fact that is questionably anti semitic, but could also simply be a go at Israel's right wing government. RLB retweets and endorses the whole article, and she's out of the shadow cabinet without even a conversation with Starmer. That's pretty tough, but may be it's what Starmer promised the Jewish community.
I don't think the Left will disappear. They may split from Labour. Clearly there are two parties within one party. Brexit solved a similar problem for the Tories. I can't see a neat solution for Labour atm.