Yes, I know it is early and I have inquired lightly about this but it seems upon looking at previous years of winners we have not seen any sing classic soprano songs. Most of the winners are singing belt songs from modern musicals.
That was my D but she was a classical vocal and not a theater winner. She just graduated CCM MT last year. In 2015 a winner sang Till There Was You and last year there was On the Steps of the Palace that is more of a soprano feel. You really just have to do what you do best.
My D got an HM MT this year - going to the NY regionals, and is a non-belting soprano. She did a classic song the year before and did not get in, but re-evaluated, looking at the winners that year and definitely felt a more contemporary vibe and this year she did a song by a contemporary composer. While it was not in the classic tradition and didn’t go nearly as high as she can go, it also was definitely not a belt and not a mix really, either - it did convey character.
D submitted ‘Till There Was You’ for 2016, for a funny reason - it was the shortest song she had, and they asked for 2 min or under. Won merit… Also submitted in classical voice, but this is one of the most competitive categories, with a very few winners, give or take.