Neural net synth would be even easier to trace. It’s quite hard to set up an aws account via untraceable currency and an untraceable phone. I did it when I was 25 or so, and it took about three weeks of planning and execution just to get the cards and phone.
Given the sophistication of the attack, I wouldn’t say it’s impossible they have neural net experience. But as someone who spent a good chunk of time trying to get Dr Kleiner to sing (https://m.youtube.com/watch?v=koU3L7WBz_s) it wasn’t remotely easy a year ago to do this locally.
Using “say foo” in macOS would’ve been the most straightforward solution, I think.