The bible does distinguish generations quite well, so I doubt Jesus had any problem when he spoke of generations as being singular entities. Interestingly it does discuss overlapping generations in such places as Gen 6:9 which speaks of Noah as having " proved himself faultless among his contemporaries". The footnote states "generations" - NOT the singular "generation"
It is highly probable that Noah was viewed this way by sons, brothers, peers, etc. which would form several generations, all ovrelapping. "This generation" at Matt 24:34 (and the other ten instances in Matthew alone) gave no indication of so called overlapping. This was proven true just three decades or so later with the destruction of Jerusalem in 70CE within the generation he spoke of - the apostlel John was one for sure who lived beyond it. If he was "evidently" wanting us to think of overlapping generations he could have used the term "contemporaries" or some other word quite easily - but he did not. he was and always will be speaking of the singular generation because we have evidence he was right.
Expect some back-peddling in future WT issues on the subject.