The article is mistaken, even given the date it was published. There are binaries for PhysX on the developer site for linux. They are pretty broken, but they do exist. We have license, much to my chagrin, and can release applications on linux that use Ageia. I'm not sure why Epic would be having problems.
Also, you DO need the physics to run a server. I'm not sure why anyone would think you don't. You still have to simulate the interactions in the world, which requires physics.