The idea behind WUDO is similar to torrent sites that make large-file transfer easier (in this case, those increasingly frequent Windows 10 updates) by enabling users to share directly with each other the files associated with updates. In a nutshell, without your knowledge, Windows has signed you up for peer-to-peer-style file sharing with the millions of other Windows 10 users constantly updating their OSs to help those updates download and install faster, by spreading the bandwidth demands across the entire Windows community.
Unfortunately, your network bandwidth is limited; and now it is being directly employed by Windows to share updates with other users to ease the burden on Microsoft’s servers—and presumably to make things go smoother for you, too, when it’s update time on your end.
Now, the latter likely usefulness of this feature to you and others notwithstanding, you will almost certainly want to keep it disabled since you use your broadband for virtually everything you do on your computer, while Windows updates, as incessant as they can seem, are still relatively sporadic events compared to everything else you do.
Ideally, you’d be able to turn on the WUDO feature only just before downloading and installing Windows updates to help ensure the fastest update downloads. Unfortunately, unlike Windows 7, there is no option within Windows 10 to stop automatic downloading of Windows updates: