The question, many years old as it is, was whether there's a specific article that covers that specific crime, so I don't know where you're going with your Article 32 remark or the question you opened your post with. The OP wasn't expressing any doubt that conspiracy to conceal a crime was serious, he or she wanted to know if there's a specific article that covers it or if it's one of those Article 134 offenses. Where did you get the idea that the seriousness of the crime was being doubted?

Why would you doubt that conspiracy to conceal a crime is a serious offense in military law? An Article 32 hearing is just the first step in the investigation and prosecution of such crimes. Article 81 covers conspiracy to "commit an offense", and I submit that concealing a crime is very much an offense. General article 134 should cover it, though violent assault and rape should be a very major crime in its own right.
http://www.yelmonline.com/news/business/article_d062424f-fbb7-5a26-8e9 b-000b20bef1d7.html
"Article 32 hearing set for Soldier charged with conspiracy to assault fellow Soldier."