It seems I was mixing up k6 cloud script.js with k6 --out cloud script.js
From Cloud :
Don’t confuse k6 --out cloud script.js (what this page is about) with k6 cloud script.js. While the former means that you run k6 locally and stream the result to the cloud, the latter means that you upload your script to k6 cloud and tell the cloud infrastructure to run the entire test for you. In this case you’ll only see status updates in your CLI, but in all cases you’ll be able to see your test results at https://app.k6.io.