Yes, it is out - got back my car today with it updated. The dealer read me the highlights - mostly sensor and module calibration tweaks, but nothing that you will notice while driving. For example, new oil level check procedure, Chinese language support, etc. Although they did update something to do with the engine cover and luggage compartment latch logic, so you may notice that. Like any software update, it probably includes an array of other minor improvements that they didn't bother mentioning. For example, I noticed that if you view tire pressures, by default the display keeps showing you that until you explicitly navigate away from it, instead of using a timeout.
Car drives the same. IRIS the same. Somewhat odd that they would designate it platform 12, which, being an integer, kind of implies some major changes. But engineers have their reasons!
p.s. one thing to note is that it will reset preferences, such as choice of tires in the menu. If you have Corsas, remember to manually select after the update. ISG settings, too.