The July 2013 Study edition says that "For many years we taught that the Great Tribulation broke out in 1914"
This teaching has been largely forgotten or swept under the rug. Why mention it now? - unless they want to use it to put a new spin on 1914.
Since the GT did not begin in 1914 - they " THOUGHT " the outbreak of WW1 was the sign - it follows that it was not the sign for Christs second presence either, or the beginning of the separating work (the latter now future) when he sits down on his throne and judges the nations.
BIG noolite on 1914 is coming, and it depends on this old 1914 teaching.
HB