I'd like to know the source too!
Whilst many sincere ones have looked back to specific dates to ascertain the fulfilment of prophecy ...
The British spelling of "fulfilment" and the use of the word "whilst" both indicate this did NOT come from WT HQ in the USA.
Also, the misspelling of "slave" as "salve" in the posted excerpt makes me question the authenticity of this alleged release. The WTBTS is wrong about a lot of things, but they are meticulous about their copyediting, particularly when it comes to anything that is going to be published. It's one of their tells.
UTR: Is that a transcription error on your part, or is that mistake in the original?