Interesting. Thanks Earnest.
The Watchtower endorsed the idea expressed by Yoder, Penner and other Christian pacifists that Peter's possession of a sword served as a fulfillment of Isaiah 53:12 in the 1983 article, Walking With God In a Violent World
However they explicitly walked that idea back in (at least) three private letters that I have firsthand knowledge of and said that the "brief statement" on page 19 should not be viewed as an adjustment to the existing idea that it was the manner of Jesus' execution and to a lesser degree, his trial and arrest that actually fulfilled the prophecy.
I was curious about your inclusion of the reference in the quoted passage above, so I went and looked in the 2013 edition of the NWT and sure enough, it is there now. That is a departure from their 1984 reference Bible, which did away with that reference.