iOS 16.2 did NOT fix the iPhone bug of wallpaper on Home Screen going to black

That is not a bug, that is a new feature of Do not Disturb that lets you set different wallpapers for Focus settings. Go to Settings/Wallpaper and create new wallpapers (don’t try to use ones set up with a previous version). Also delete any black wallpapers.

if you have updated to the latest version then it should be fixed if not you may have to reinstall the os. you can backup your data using a Mac or iCloud then go to  Settings- General- Transfer or reset iPhone- Erase all content and settings. make sure to save your data using iCloud or a Mac or another method.

A bug is something that does not do what the process was designed to do. But wallpaper is behaving exactly how it was designed to work. You may not like Apple’s design, but that does not make it a bug. iOS 16 allows wallpapers to change based on several options. If you choose a different option and there is no wallpaper designated for that option it will be blank. I encountered this when I first moved to iOS 16, but I now appreciate the flexibility of having different wallpaper for time of day or focus settings. It’s really convenient to instantly see that Do Not Disturb is on because the DND wallpaper is displayed.

And in my case there were no black wallpapers. There is one and only one wallpaper that has been recreated multiple times.

So Disagree this isn't a bug.

IMHO -- I suspect this is related to iCloud. If one is in a bad service area and the photo has been moved to the cloud and the phone tries to get it back and that fails IOS gives you a blank screen.

So any ideas when this will be fixed?

Things don’t “move” to iCloud; they sync to iCloud, so everything in iCloud is also always on your phone, and vice versa. Photos don’t have to be downloaded to your phone, because they are always there.