on upgrades no keyboard settings are written to the system.  Was us set as the
keyboard before upgrading?

I don't think so (but can't verify): I had done a testsetup and I normally choose IT keyboard because that's what I have.
Also, why bother asking which keyboard to use if the setup is not written to disk? What's the problem with doing it? (I'm curious)

it's only for typing in answers into the dialog boxes in the installer when
you're in Upgrade mode.