How is it going to help? The link is of a Sikh hunter. Fine, but what good does that do the lazy Sikh who ate khulla maas in a restaurant?
By the way, for the OP, yes, it's against rehit to eat khulla maas.
That is completely normal. This seperation of men and women is only found in western gurdwaras. In India families sit together whether it is in the Gurdwara proper or the Langar hall.