I don't remember hearing about the NZeTA from Disney, either. I'm pretty sure I read about it here on the ABD Forum, with folks heading on the early trips talking about needing one.
However, they did make sure we knew about the requirements for a Visa for the China trip, and they recommended an agency for that (CIBT). But that's just info, and it's up to you to make sure you get it.
Sayhello
The NZeTA requirement is listed under the Travel Documentation section of my "handbook". I had already used the NZeTA app to get mine before ABD sent me the handbook link thanks to this forum.