MLG Pro is Fraser's parody of hardcore gamers, VGA being the exact opposite of them. Fraser is totally MLG Pro, he just hasn't been sponsored by the league yet. Besides, how MLG you are isn't determined by how many sponsors you have, but by how big your Gaming Dick is.
Typically, these jokes are aimed more at hardcore gamers that may be watching the show in the chatroom that take games way too seriously, like Blastoff365, rather than the actual league. In this context "MLG Pro" is used more as an adjective of how L33t a player may be, and is often accompanied by ridiculous sex feats such as "taking a gun apart with your feet while jerking off and having sex with a girl at the same time."Fraser has considered making a new show with the express intent of trolling hardcore gamers during the Deus Ex episode, and asked the chatroom to come up with alternate titles for this show, many of which included extremely ridiculous vulgarity.
MLG Pro can also be a battle cry, in the style of "Leeeerooooy We Beat the Dragon!Jeeeenkiiiiiins!!", first used in the LIMBO episode. In fact, one variant is "MLG-roy Jenkiiiins!!!"