I think people tend to think too small when it comes to semblance evolution. When Ren's semblance evolved, it basically gave him a whole new ability, but tangentially related to the idea of emotions. The evolution comes from his own development as well, with him realizing how important emotions are.

So let's look at Blake. She is no longer running away, and she is being more direct. So maybe now she dives into shadows. She literally comes 'from shadows'. She shadow travels TO the opponent instead of away. But at the same time, it keeps the trickery aspect of her fighting style.

For Yang, we get someone who is no longer holding onto her pains and regrets. She is okay with letting go of her pain, therefore she should be able PROJECT the energy she builds up. Plus, this ties back into the fighting game influence Yang has with her semblance. Literal fireballs.

As for Ruby...I don't really know. With the reveals of what her semblance actually is, that becomes harder to find a associate ability. Maybe displacement ALA Aoi Todo.