It is true: Microsoft has said several times in Insider blog posts that most settings reverts during updates are considered to be bugs, and if you find one the best place to file that bug report is Feedback Hub. If you care to see that corrected, I can only recommend you try searching Feedback Hub for your specific issues and filing them if you can't find existing reports.
> So you never had to use the Network Adapters window? I need that one pretty often, the new one in Settings is not adequate.
Can't say that I have a regular need for that, no. Most of my devices have only a single network adapter in active use at any given time and the modern Settings has been adequate for my needs.
> How do you add or remove features from Windows, like HyperV or WSL?
The last time I activated or deactivated either of those it was directly in PowerShell.
This is simply not true. Nowadays I have a freaking ps script to run after each upgrade, to set things back how I configured them.
> Personally, since a major Windows update or two ago I only have one settings panel I actively use that is still a Win32 dialog and not directly in the modern Settings app.
So you never had to use the Network Adapters window? I need that one pretty often, the new one in Settings is not adequate. How do you add or remove features from Windows, like HyperV or WSL? That one is also inside the old Add/Remove Programs applet (the features on demand in Settings app is a different mechanism, with different content and applications. Yay for consistency).