What is this "swscan.apple.com"?

Is there an option to remove it, or resume to whatever the default was?

Solution 1:

swscan.apple.com is the default -- it's Apple's site that serves catalogs and metadata about available software updates (the updates themselves are served from swcdn.apple.com). I'm not sure why it's shown explicitly there; maybe it's being set by a profile, or something like that. But if it's being set by something explicitly, it's just being set to what it would be by default anyway.

P.s. According to the page for Reposado (a tool for running your own update server),

In macOS Big Sur, Apple has removed the ability for softwareupdate to be pointed to a non-Apple sucatalog. This means you cannot use a Reposado server to serve Apple software updates to Big Sur (and presumably later versions of macOS) clients.

But if you're seeing that in Monterey... maybe Apple brought the option back?