I could update this, but then it will just go out of date the next time the SDK updates, and could also break it for anyone who is intentionally targeting build 10240+ for maximum Windows 10 coverage. So I don't think there's any right build number we could choose.
All you need to do is open project settings and choose one of the supported build numbers from the dropdown, so I think it would be better just to document that instead of playing cat and mouse with build numbers.