The max AP ratio on her Q is going down by 25% on the PBE.
Zoe has a 48% winrate and a low pickrate. She didn't need a nerf at all, but you're going after the most satisfying and difficult part of her kit?
What needs to be adjusted on Zoe is the things that her opponent has no control over. They can build MR. They can dodge a skillshot. What they can't control are the summoners she picks up from minions and a surprise stun hitting them through a wall.
If you want to nerf Zoe in a way that makes her less frustrating to play against, do this:
1) Add a sparkle effect on walls where a Sleepy Trouble Bubble is going to exit that wall, similar to Kayn's Shadow Step, so players get a moment of warning to avoid it.
2) Gate the drop table on Spell Thief balloons on minions by level or W rank so Zoe can't pick up a free Ignite at level three and double-Ignite her lane opponent for an easy kill courtesy of RNG. She should only get defensive summoners to smooth out her laning phase, and the aggressive playmaking summoners later so no balloon is useless.