I would not say, that it is a cucial requirement. Back in the 90, there were not really Game Servers but Peer to Peer connections and the game itself took care of a server behaviour. This is something, you can actually do with EasyWebSockets.
I am trying to give the best possible functionality with the PlugIn to allow sending object specific coordinates, a Chat System and maybe other stuff.
In Addition, you can also set up 2 different games, one version to be run as a client only Game and one that mainly runs as a Server and broadcasts the results. (okay, you need to have a Browser somewhere that is running the server Game all the time. But it is possible) :)