You can literally kill off anything in windows, albeit with some effort in certain cases. Right down to their telemetry services everyone hates.
Beyond that though, such a system would be quite a lot of load on the hardware running it. In fact, many low end hardware combinations that support 11 likely won’t be able to support such a feature. Not including an off button would be silly. In fact, not making it opt in, similar to gaming clip systems, would be a terrible idea.
Comparing it to a locked down OS with a cloud service tie in I’d like comparing oranges to cars. All signs point to this feature being fully local. What are they going to do, hide gigabytes of video from you just to waste space?