Re: Genuine curiosity...
For NCSI? Same way as on any previous version of Windows. Registry or group policy (local included).
Devices and printer images? Same.
Windows Update? Same, or at the firewall as always.
Just because there's not a nice GUI interface doesn't mean you can't disable it. And it doesn't mean it's alone in that among the THOUSANDS of hidden Windows settings for everything else. If you've ever deployed GPO, you'll be amazed how much stuff there is you can turn off that you can't do other ways, and how much even GPO doesn't cover so you have to make your own Administrative Template to do it.
How do you disable the accessibility button on the login screen, which can be used to make the login screen almost unreadable and most people won't be able to put it back? Like everything Windows, the "official" way isn't a one-click setting in control panel, just like all the things you mentioned.
But they're all still there in the Registry, in the same places, available on freeware tweak utilities, etc.
Did you know that you can't add a keyboard language if you disable Windows Search service? Try it.
It doesn't mean 10 is any worse in this regard than ANY OTHER VERSION. Windows 7/8 does not have a settings box anywhere but the registry for NCSI, for instance. And if you want to enforce that settings, you're not going to rely on remembering to click a box, you'll enforce settings via GPO, a tweaker utility, or a bunch of Regedit scripts.
Just because it's not one-click doesn't mean you can't do it if you want to.