They did plenty. They stopped Azwel from bringing his plans to fruition and either saved Grøh or put him out of his misery, though my money is on his redemption being the canon choice, though it is also bizarre that there was a choice to begin with, with everything else being concrete and decided.
Libra of Soul is undoubtedly canon, home to many side events that weren’t big enough for Soul Chronicles, and so the Conduit being a hidden truth to history is both a deviation and also not a deviation, on the same level as Grøh and Azwel. It is debatable on whether or not they are new entities, thus a deviation, or they were always there, just kept out of the public view. Either interpretation is valid, though if you’ve paid attention to my posts, I lean towards the latter.
Zasalamel and Cassandra remain the only two characters so far to have direct contact with the future, so everyone else is just playing their parts as they did originally. And Cassandra even, still mostly remains the same, because she is keeping knowledge of her visit from her future self from everyone, even Sophitia. So you could even argue that this is also not new, should we find ourselves in a closed time loop scenario. Zasalamel, then, remains the outlier, no longer wishing for death, knowing of Algol’s resurrection before it happens, but you could even possibly say that he keeps so many things to himself in the interests of preserving and protecting the swords, this may also have been the original turn of events. I say that last bit with reservations, if anything is to come of a new history, Zasalamel will surely be the one to bring it. Otherwise, history seems destined to repeat itself.
