The opposite is more likely. Updating baseband firmware is like updating your network router; it's likely to briefly interrupt the connection. They're applied

The opposite is more likely. Updating baseband firmware is like updating your network router; it's likely to briefly interrupt the connection. They're applied by the operating system, so the OS is going to choose to automatically do them when the phone is locked with idle network traffic. It's probably more of a sign the phone is not in use.