Cocoa in a note means the smoke suggested chocolate, cocoa powder, or cacao husk. It is a frequent companion to maduro wrappers and to some longer-fermented leaf. Association is not proof. Nobody dusted the filler with baking cocoa.
The word is ordinary English. We will not build a pastry vocabulary around it. If a cigar tastes like chocolate to the reviewer, the review will say so and stop.
Related glossary: earth, leather, strength vs body.