Looks like they are replacing the Zahn trilogy with the Aftermath trilogy.

The Zahn series never was film level canon. Now that it is legends it is not even in the same universe it is in another discarded continuity altogether.

Obviously since Star Wars is no longer different tiers of canon but all one canon.

Since the Legends continuity is no longer being published in it might as well be erased from existence.

Going forward there way no way they were going to have competing timelines or a multiverse.