Is the term “fossil fuel” a form of propaganda introduced to obscure just how plentiful crude oil actually is?

This actually is the case. It is an archaic term. It is a term born in ignorance, so we would say: "It is actually obsolete and long out of date as a way to characterize the oil supply." It is not that all the oil is readily at hand, there may be some very sophisticated exploration and mining operations needed to pull the oil from the Earth in the quantities desired, but there are plentiful reservoirs scattered across the globe.