The article doesn’t quite capture that a16z, in my memory, played a major role in popularizing podcasts as a direct media strategy. Fred Wilson, for example, was commenting on it way back in 2014 [1].
Marketing is the commercial term (brand ambassador, Orwell sleeps soundly). Propaganda has a lot more coercive connotations.
It's not necessarily nefarious, but if there's a need to do it in the first place then it often has self-serving end goals in mind.