I think he should be Maul, but doubt he will be. Just one of many more lost opportunities by Lucas as a writer. Consider this as an easy "what could have been":

Qui-Gon's saber being blue, Obi-Wan's being green. When Obi-Wan's is lost during the Maul duel and he takes Qui-Gon's, he then wears it for the rest of his days as his own. This also would explain why Luke's own saber, which he built from parts in Obi-Wan's hut as an unfilmed (but written and included in comics and in the novel) scene in ROTJ, ended up being green, and not blue.