"A conspiracy theory is an explanation of an event or situation that invokes a conspiracy without warrant, generally one involving an illegal or harmful act carried out by government or other powerful actors." - Wikipedia
In this case, the word 'conspiracy' comes up because the post openly refers to a 'global cabal' (i.e. - powerful actors) who, it is claimed, were involved in illegal and harmful acts -- after all, one of their goals is said to be 'elimination of the population'. This is, by definition, a conspiracy theory.
That doesn't absolutely and forever mean it's not true. BUT that the only piece of evidence offered is a recording found on torrent does not make it look very strong. Further, what is this "theory" explaining? If this powerful global cabal is planning to eliminate the population, why do people live longer these days, at least in the West? It has been nearly half a century since the alleged meeting at which the recording was made. Is the global cabal so bad at their job that despite their power and secrecy, their efforts have failed to reduce the population or reduce life expectancy?