I have an 55" Sony X900H television, which has the "old" Android TV Launcher.
As far as I see on https://www.android.com/tv/ site, with every language, it shows the new UI, and last year (start of this year too) almost every European country got the UI update.
As this article says, the tv should have received the update.
Any idea, how to force the Play Store to get the new update, or why I didn't already get it?