You might have noticed that there are new properties available in Windows Autopilot user-driven scenarios, both for Azure AD Join:

And for Hybrid Azure AD Join:

But if you try it, you’ll find that they do nothing.  That’s because these new options require changes that are present in Windows 10 Insider Preview builds and will ship in a couple of months as part of Windows 10 2004.  So if you want to try it out, grab one of those builds.

There is one key limitation with these settings (beyond the OS version requirement):  In order for them to be effective, the device will need to be connected via Ethernet so that the Autopilot profile containing these settings can be downloaded and processed early on.  If you are connecting via Wi-fi, you have to choose the language, locale, and keyboard layout manually before you can make a Wi-fi connection, and therefore it’s too late to apply these settings because you’ve already passed that point.

Another important note about these:  If you configure them, you won’t be able to initiate a white glove deployment any more, because OOBE will automatically progress past the point where you can press the Windows key five times.  So, if you want to automatically choose a language, don’t do white glove; if you want to do white glove, don’t configure these.  We’ll try to remove this restriction in a future release.  (Alternatively, you could choose not to make a network connection, e.g. don’t connect the Ethernet cable, until after you’ve pressed the Windows key five times.)