I still have no idea how a sniper support will work, much less be consistently effective on consoles. The only thing I can think up is if the gun uses a beam like Zarya's gun instead of hitscan bullets.
Zen is great if your team realizes that just because you pick him doesn't mean they can drop Lucio/Mercy, lol.
One thing that I think could be invaluable is giving vision of the enemy team, even if it's one person. Much like how I thought discord initially worked as Zenyatta.
Other than that, if that teaser was anything to go by, making her heals through sniping could possibly a nightmare if it doesn't have a auto lock like Zarya, Mercy, Zenyatta.