Not all speeches made are published. They come from those that attended, their notes, and transcripts.
I really doubt that the Political Bureau of the Central Committee of the Communist Party of the Soviet Union has opened their archives; but maybe it is available on the CPUSA archives.
http://dlib.nyu.edu/eadapp/transform?source=tamwag/rcp.xml&style=tamwag/tamwag.xsl&part=body
Guide to the Revolutionary Communist Party, USA. Collection
Well, you make my point. If it wasn’t published, and nobody can say where it came from, there is no resaon to believe it’s real. BTW, I did a google on it, and the only place I find it is whackjob conspiracy theory websites. It is doesn’t seem to appear on any mainstream news, historical society, university, etc. websites.
You are aware that CPUSA and the Revolutionary Communist Party USA are two different organizations? It’s not entirely clear from your post. CPUSA is the Communist Party USA, a legal political party in the U.S., while the RCP is not an actual political party, at least not a legal one. The RCP is Maoist.