That’s a bummer @tommy. However, I thought on another thing…
Given than an user already enabled access to recordings with timestamps, what if I create an app that listens to the “record.completed” webhook ( https://marketplace.zoom.us/docs/api-reference/webhook-reference/recording-events/recording-completed ), then I extract the Timeline file URL from the payload, and download it in order to process it and get the active speakers information that I need based on the “ts” and “users” attributes of the timeline json.
Moments later I found this thread: Access to zoom recording and speaker activity data in which you proposed that same idea and that made my day 
Thank you @tommy and Tommy of the past!