As you have pointed out to RTFM, well, there is simply no manual available which exposes the functionality behind the thousands of windows threads running inside svchost. Threads don't carry unique ID's in that the thread ID will be different each time that process is executed.
You will notice a few of them which of specific names, however threads you cannot simply shut down as multi-threading is called that for a reason, that one thread which may be problematic, may have several very helpful nested threads and shutting it down could crash your system. I'm a software developer and I create threads quite often. I think I understand a little bit about threading. It's a complex topic.
See this one here? It's downloading at 500kb/s. It's been doing that for several hours now. Feel free to Google svchost.exe+0x4380 or find a manual on Earth that covers that. You won't. Why? Because as I have pointed out threads don't carry the same unique ID.
There are plenty of settings available to manage windows download, but ultimately without 3rd party software, you cannot stop Windows update, only delay it. You are only given so much control over what data streams to and from your machine, but for the most part the internet is filled with "threads" about people wondering where their data is going.
Note: Even with Windows update completely disabled, svchost and it's multiple variants, continues to stream data to and from my machine to god knows where and why.
Edit: I think what I find most fascinating about Microsoft fan boys is that they don't seem bothered by this at all and are happy to just turn a blind eye. People who complain are simply told: "Well if you don't like it then don't use Windows" .