I suspect that you'd still need a Windows Server license to start off with. It may or may not need a VM under the hood, but that's a MS thing to figure out. They certainly couldn't license a container the same way as a full Windows VM or bare metal install.
Id expect that since the idea is having your windows container running on a windows host, that each version of windows server will have a "this edition allows X number of containers" limit. This would line up with how they treat VMs. Lets hope the number is 5x the current VM limits.
I thought the whole point of containerization was that you ran apps in a container, but the container doesn't contain an operating system. (You have several containers on one instance of the OS, not several VMs, each with its own OS. That's how it works in Linux, anyway.)