At least only major service-pack level updates actually cause everything to install/reinstall. It's kind of funny how Microsoft has their official "one version of Windows" marketing when there are clearly different versions with difficult names ("anniversary update").
But I laugh at your comment because I, as well, spent a day uninstalling the re-installed bloatware apps and re-installing my VPN client.
You completely misunderstood the whole point. The one windows does not imply it is one thing which runs on many thing , not at all. one windows whole point is you can use same design/API for your program and target as many device as possible, kinda like Java.(but not compile once , run everywhere part)
Sorry I meant the "Windows 10 is the last version of Windows" marketing. The anniversary update was a whole new version of Windows and not just part of continuous stream of updates.
But I laugh at your comment because I, as well, spent a day uninstalling the re-installed bloatware apps and re-installing my VPN client.