Sorry, that was presumptuous of me. 'TCP stack' just means each container can have its own IP and services. Each docker, and in fact each Linux host can have as many interfaces as you like.
I imagine you would get a conflict when you try to go to 192.168.1.2:8000 or even localhost:8000.
You're free to run a service on port 8000 on one IP and still run the same port 8000 on another ip on the same subnet. However, two services can't listen on the port at the same ip address.