I would like to point out that the game CURRENTLY has a system basically identical to this. You flag yourself LFG and type your role in the comment and the list itself shows ur class and level. Heck you can even kinda say what u want to group for. But nobody uses it.
yeah, wow had it before lfd. It was useless.
EQ had it before wow existed: it was useless there too. If you wanted to pug a group you went to the zone you wanted a group in and spammed ooc for it, or spammed in the game hubs like PoK.