I received an email from Comcast
this is only free if you only have internet service
Included with your service: a Flex 4K streaming device
It is basically like a Firestick or Roku box. It is free and one nice thing is that it does combine the shows from Amazon and Netflix together which is pretty nice.
One odd thing is that a YouTube review says it does not include HULU, or CBS but their web site says it does?