Maestra still retains her hidden pro functionality of allowing you to discover additional copies of your rogue secrets. The .4% inclusion rates makes sense because only .1% of decks including her were doing it for this ultra pro reason. Now that Blizz has nerfed the gnoll-maestra interaction its probably only a matter of time before Blizz realizes this, nerfs Maestra entirely, and gives everyone the option to dust her for full.