No - not by Jehovah's Witnesses.
There seems to be no clear line from the Society on how much preaching needs to be done before the "end". The "stones would cry out" principle is sometimes aluded to but I was/am a little vague on the official line.
If we take the preaching in the USA and assume that everyone has at least heard of Jehovah's Witnesses, this has taken over a hundred years effort in what is basically a Christian, population now 250 million (very approx. I know). Now, take China and India, these represent at least a third of humanity, approx. 2 billion. I know there are Witnesses in China and Indian, but in orders of magnitude, they are virtual non-existent. Besides, these are non-Christian countries and despite quite a large effort post WW2 to send missionaries in, there was none of the explosive growth experienced in Africa and South America, areas of the world already Christian.
eyeslice