[b112]

This isn't true.

debconf plus update-alternatives plus display manager login menus means configs are sticky.

There are rare exceptions, but unless Ubuntu is very strange, deviating fron Debian significantly (and stupidly), what you're saying doesn't happen.

And it is separate. The package manager is calling update alternatives. It's not some ad hock wild west.

You're either asked, or alternatively no change is made.