It also encourages people to make some of the sets again, as well as do the events for some of the sets again. If someone wanted full Homam to morph or lock their gear to, they would have to do Limbus until they got those pieces. If someone wanted that shadow lord armor set from the past, they'd have to help with campaign and actually care about the systems in place for WotG to get their set. Would be no different than the people who run old raids in WoW every week since the implementation of transmogrification.