What the Xavax need now is a needle to stitch themselves back together and thread their way toward a new path.
Selenia was a battleaxe. Big and flashy, sure, but impractical for the current situation and utterly incapable of performing the delicate work required. Can you imagine her negotiating with any of the southern powers, much less the Vix? She knew that her period of usefulness has ended, just as she knew the Imperium was doomed when Iuz betrayed her again. Better exile than cause her people harm just by her presence.
If I could change anything about how the Path of Ashes went down, I probably would have brought the Xavax to First Oligarch.