I think that Medieval revival was a trait of Romanticism, but in a larger sense. The Romantic thinkers were attracted to the idea of past cultures. Cultural expressions of the past were seen as a stark contrast the modern reality of materialism and conformity that faced the Romantic thinkers. Cultures like Greeks and Romans held interest for the Romantic thinkers because they were so diametrically opposite of modern culture. Medieval revival held interest to Romantics in so far as it being an antiquated culture. It was a time that had passed filled with heroism, individuality, and the pursuit of "the good, the true, and the beautiful." Medieval culture was revived in the Romantic thinking because of its link to the past, a time that was no longer present.
It is in this desire for something that is not present where the tone of melancholy is prevalent in Romanticism. For the Romantic thinker, the construction of the modern setting is one in which the notions of self and the pure embrace of that which is beautiful are noticeably absent. Melancholy is found in the hope to bring back that which is gone and in recognizing that what is left in its place lacks redemptive qualities. The tone of Romantic melancholy is seen in the drive to replicate what is absent, thus leaving a sense of longing and eternal pain. It is in this where both qualities are present in Romanticism and linked to one another.