It turns out we almost got to see Ahsoka Tano on the big screen back in 2002 in Attack of the Clones, albeit in a roundabout way.
I think it was the name given to one of the [young Jedis Yoda was training] in Attack of the Clones.
There is a notable scene in Attack of the Clones which sees Yoda training a young group of would-be future Jedi.
Dave Filoni, who helped bring Ahsoka to life alongside franchise creator George Lucas, recently went over the character’s history in a deep-dive interview.