This find adds nothing new to the Divine name argument, the reason the Name was written in Hebrew letters is believed, with good reason, to be a warning to the reader to substitute "Lord", otherwise why not translate it in to Greek ?
As one of the academics quoted above observes, the Text was not static, so it could well be that by the 1st Century copies of the Septuagint which the N.T writers used did not contain the Name in Hebrew, simply one of the Greek words for Lord.
We will never know of course whether the divine name was written by N.T writers as autograph copies of N.T writings will not be found, in all probability. Of course, if a Copy were found containing it, we could not know for sure they uttered it aloud, certainly Jews did not by that time, and many early Christians were orthodox Jews , surely there would have been a furore about uttering the Name if that had suddenly become the practice among Christians ?
The debate will no doubt continue, but my default position is that JW's are wrong on everything.