Graves is also a qualifier for ADC, and Morgana is a Qualifier for Support. You need to keep that in mind, especially since NOW Morgana is perceived as a support.
You're right about gender, although I have seen them mention it in some victorious threads.
Jarvan's now considered a Jungle, not Top, so technically we have:
Top: 1
Mid: 1-2
Jungle: 2-3
Support: 1-2
ADC: 1-2
I'd say the odds favor Top, but could be mid/support/adc. Jungle is probably unlikely. Mid was last year, so almost entirely excluded.
If we exclude rework imminent champions:
Top:
Support:
(Nami is unlikely due to her new skin)
ADC:
(Ashe unlikely with new skin, although...... the art added for 10th aniversary for Ashe as the 40 looks a LOT like a Victorious Teaser. Ashe also has a Conquerer Skin, which puts a shadow on that.)
My guess is Zilean or Teemo. Neither have Conquerer/Championship skins, both have lots of skins. Jinx is possible, but doubtful.