I noticed the following in the 3rd article in the same issue of The Watchtower (my own comments in blue):
In his detailed prophecy about the conclusion of this system of things, Jesus said: “This generation will by no means pass away until all these things happen.” (Read Matthew 24:33-35.) We understand that in mentioning “this generation,” Jesus was referring to two groups of anointed Christians (um... no). The first group was on hand in 1914, and they readily discerned the sign of Christ’s presence in that year. Those who made up this group were not merely alive in 1914, but they were spirit-anointed as sons of God in or before that year.
The second group included in “this generation” are anointed contemporaries of the first group. They were not simply alive during the lifetime of those in the first group, but they were anointed with holy spirit during the time that those of the first group were still on earth. Thus, not every anointed person today is included in “this generation” of whom Jesus spoke. Today, those in this second group are themselves advancing in years.
It seems they're saying that the new 'overlapping generations' generation can't be used beyond just the one 'overlap'. Apparently they're trying to rein in speculation about the new 'overlapping generation' allowing an extended period before 'the end'. They drum this point in further by suggesting that the overlapping generation (which is also the same 'generation') is also "advancing in years". ('Discerning' JWs should interpret this as "panic".)
Of course, if they later decide they do want to extend the period further, this 'new light' will simply fade into obscurity.