Stop inappropriate settings changes during updates

• Did you change your Lock Screen/Home Screen Wallpapers. You can now add a Focus setting to a Wallpaper and some of the included Wallpapers will include the Focus with the Wallpaper. Here is a similar post with those options.

How do I set wallpaper and turn off Do No… - Apple Community

• I haven't seen where DND was turned on following the update, but there was a notification on the Lock Screen that asked me if I wanted to have the phone automatically manage notifications for how I use the phone and I said no. I don't remember that Notification specifically mentioning Do Not Disturb, but that is exactly what it does.

The one Setting I have seen that is changed following the update is Automatic Updates. If it was turned off previously and you manually updated iOS, then there is a message after it has been installed on the Software Update Complete page where it says that future updates will be performed automatically and if you don't want that to happen, then you can go into Settings and turn it back off. I have seen where users did not read that message and simply tapped OK, then wondered why the next update was automatically installed.

For a specific Setting that can be turned on to prevent any changes, no there is not one. You can send Feedback directly to Apple though.

Feedback - iPhone - Apple

I have found that some settings are pre-determined by Apple in updates and upgrades that cost time to undo when not previously selected by the user. True on the Mac, and also on i/Pad/OS. There is nothing you can do to prevent this, as it is Apple dogma.