It’s been the default since 2015 when Windows 10 launched, although there was an obvious button to opt out during first-time setup back then which was then respected permanently. It’s got gradually less prominent over time, and maybe the article’s just doing a really bad job of explaining that it’s no longer something where your initial preference is permanent and it’ll change back to the default every so often.
Typically Windows applications bundle all their dependencies, so Chocolatey, WinGet and Scoop are all more like installing a Flatpak or AppImage than a package from a distro’s system package manager. They’re all listed in one place, yes, but so’s everything on FlatHub.