Why do I get the feeling that Sivir will just try to get away from this as fast as possible?

Of course she could return to Azir, taking on the position of Shurima's future queen and preparing to fight Xerath. But that's definetly nothing she would do.

"Hmmm what is a place that is far away and has lots of cash? Bilgewater... nah... Ionia? Currently full of Noxians. How about Piltover and Zaun then? Ok, GOODBYE SHURIMA, got to hell for all I care, you will not be missed. Stupid ascendants can fight their age old wars, but don't bring ME into that."

She sounded kind of heroic when she commanded Nasus to defend the city, but I do get the faint feeling that this was just an act to get rid of him at that moment. That's definetly something she would do...