The embedded systems I work on are never internet connected and updated manually by trained service technicians when necessary.
Like the discussion at the top of this thread, we've really muddied up the waters when it comes to defining "embedded devices".
There are devices like mine, which are the early definition of the term (single purpose, low cost, tightly defined I/O) and then we have low cost highly compact computers, literally servers, that can be multi-purpose and are internet connected 100% of the time by design.
