There was another long term member of ET, Visaria, who made a similar thread also having bought the course from Al Brooks. I'm not sure what the conclusion of it all was.
But it's not uncommon with enthusiastic starry eyed neophytes following this or that guru who eventually stop posting. Either they succeeded beyond their wildest dreams and decided to stop posting on ET or maybe their results fell short of their expectations.
Visaria was an experienced trader from what I gather, though. Maybe he just got tired of ET or maybe he even registered with a new nick (like it seems so many do here).
https://www.elitetrader.com/et/threads/i-have-bought-al-brooks-trading-course.294140/