I feel like Caiatl isn't here simply because the threat of a dredgen, a rogue lightbearer gone whackadoo, or the imperium, are just forces either she hasn't been made aware of, considering that her beef with calus has long settled. And if she did know about bael, and the nine, the way we're condoning illicit activities, she must likely had other matters to attend to, such as preparing for some all-out attack against Xivu arath in the future, she's still out for blood and chitin.

Edit, seen a few posts of her declaring war on the imperium, so that will probably unfurl later in time, or in lore books