The real reason they removed where you had to be in a raid to enter one is probably due to the new pets available from old bosses. They expect A LOT of people to do Molten Core and the other raids for these pets. They keep finding ways to keep their old content "alive".
Brawlers guild is totally from the movie Fight Club with Brad Pitt. It was an underground fight club and if it was your first night there then you had to fight. Sounds fun though!