What about for companies that use a firewall ?
Does the info get sent back then also ?
Depends on the rules in the firewall. Blocking access to all of Microsoft’s distributed network of servers, without blocking other internet access, is quite tricky. Their IP ranges can change at any time.
My guess is that Windows would refuse to function correctly if it finds it cannot contact Microsoft for a long enough time period.
After all, you must have your Windows Updates...