Hello Samuli,
The Web Dispatcher is a load balancer. This is its main functionality.
But it also has some features that are present at a reverse proxy.
And ok, the Web Dispatcher fits the definition of reverse proxy that you've sent, however a reverse proxy usually has much more specific features that are not present at the Web Dispatcher (since it is a load balancer, not a reverse proxy).
Cheers,
Isaías
