no, but they wrote the most vocal/choral work of all the composers listed. therefore, they probably thought of the piano as an accompanying instrument or filling in for voice when it was not singing. sometimes you almost hear, in their piano music, the accompaniment and then the singer (like a sort of small intro and then this melody comes in). although some of the intermezzi of brahms and many of the ideas of schumann start right off with a motive (maybe not a full idea) and expand on it. they were trying to get into the grand idea of the symphony, imo, but sometimes faltered and the motives didn't get as far. brahms requiem has to have a lot of memorable melodies (as the verdi requiem).
somehow, when i think of melodies in entirety, i think of chorales singing them (with words) like beethoven's ninth symphony when the chorale comes in at the end. when you have a really good pianist - you still remember the melody without the words. maybe like mendelssohn's songs without words, or something like that. schubert, to me, stands alone in piano as a melodist that one can sing the lines to, in mozart you have great 'tunes' but they are not all singable. i guess to me, a melody is something you remember because you can sing it. i think mozart once had a bird ('fool' was it's name) and he got ideas for melodies from it (so there are some skips and warbles and stuff in his music) - that unless you are a pretty good vocalist - it's hard to imitate.
rossini's right up there, too, with opera.