Dropping the generation, or at the very least reducing the significance of it is entirely possible. The wording change in the Insight Book already removes the specific argumentation that it has a modern day fulfilment.
The overlapping teaching still gives them significant time to simply stop talking about it.
The move to online publication storage means that an increasing number of dubs will not have access to material within "approved" channels that says anything different to the current teaching. Of course the info will be there but only if you are prepared to hit the apostate sites.
Given the recent argumentation used about the F&DS Slave being more "discrete" now by assigning less and less significance to parables in the Bible I can see a time when there could be QFR that comes out with some reasoning that the generation only had a literal application in Jesus day and the discrete thing to do now is simply serve Jehovah without a time limit in mind.
The significance of the generation teaching is now only really felt by ones in their late 30s and older - the ones who lived through the use of the generation teaching (and memorial partakers) as a sign of the imminence of the big A. Give it 10 years and all the current crop of young men that become the elders of the future will have no comprehension of the emphasis and import placed on the teaching what is ALREADY 20+ years ago.