Clarify/Confirmation - Can block step with input fields be dynamically generated

G'day folks,

I read the doco saying that `Block steps with input fields can only be defined using a pipeline.yml.` while I found this script in the sample repo https://github.com/buildkite/block-step-example/blob/master/generate-notify-pipeline.sh

Just want to confirm whether or not we can generate the block steps with input fields dynamically now? If it doesn't, what's the limitation stoping it from dynamic?

Cheers,
Gary