Some linguistic thoughts on Zaun

So we got some new Ezreal lore today, and with it we have confirmation that a) Zaun used to be a Shuriman port city, and b) its old name was Oshra Va'Zaun.

I and many others had been assuming the city of Kha'zhun, described in Twilight of the Gods, was proto-Zaun. Especially because it's mentioned that people are starting to butcher the city's name; zhun could easily transform into zaun. Furthermore, I did a bit of thinking recently and came to the conclusion that Kha'zhun could mean "city of change," based on the hypothetical translation of Kha'Zix as "change-insect" (because he evolves!), and of zhun as "city" or "town" (based on the existence of Bel'zhun as well). So as you can imagine, today's reveal threw a bit of a wrench in my theory.

So here's what I came up with to reconcile the two ideas. Kha'zhun was the VERY first name of the Shuriman port city. Then people butchered it into Zaun, which became the de facto name of the city, and then Oshra Va' was added - could this perhaps mean "City of..." or "Port of..."? So yeah, that's how you'd start with Kha'zhun meaning "city of change" and end up with Oshra Va'Zaun meaning (perhaps) "port of Zaun," and eventually clip that down to just Zaun.

Sound plausible, or am I leaping here?