If you're looking to get a few questions answered regarding the commercialization process, you've come to the right place.
Has Windows IoT replaced Embedded?
Windows IoT is the replacement for the Windows Embedded product lines.
How is Windows 10 IoT Core supported today?
Windows 10 IoT Core is supported through Windows 10 IoT Core Services.
Windows 10 IoT Core Services is a new cloud services subscription that provides the essential services needed to commercialize a device on Windows 10 IoT Core. Through this subscription, OEMs have access to long term support on Windows 10 IoT Core Long Term Servicing Channel (LTSC) releases along with services to publish device updates and assess device health.
Do my devices have to update automatically?
There is not a requirement that a device be connected to the internet. The license does require that you provide a mechanism to provide an update to the device if needed, but there are non-internet connected methods of delivering updates. You can learn more here.