I wish Ahsoka was arena viably but she actually doesn't do enough damage for a place on a high tier team. She has no additional effects aside from damage (healing is useless in arena 90% the time, if a character loses protection they are 1 hit from dead) and even with her new passive giving her speed she is too slow and weak to compete with Rey, Leia and even Geonoisian Soldier.
Ahsoka is one of my favorite characters as well, and I maxed her early but I can no longer find a place for her on any of my teams, even including GW. D: