Sony Mobile is currently rolling the first firmware update for the Xperia XZs, which moves the build number from 41.2.A.0.219 to version 41.2.A.0.235. The main change appears to be the addition of the 1 May 2017 Android security patches. The update is live for both the single SIM (G8231) and dual SIM variants (G8232) across select regions at the time of writing. If you have noticed any other changes, do let us know in the comments below.
Thanks exeon!