Seems the Noxus/Ionia war is a lot longer than it was before?

Kayn's new short intro paints a picture of a child trained over years to become a shadow assassin. He was picked up when Noxus attacked, and was sent on a mission that ultimately was to help Ionia against continued Noxian attacks. Growing up implies the war has gone on for at least a decade, if not longer. I'm not 100% on this but none of the implied meanings seem to indicate Noxus' war failed and continued raids afterwards.

So, if true, this does dramatically affect the relationships between the two nations.