Another possible interpretation is that fans and commentators and the general consensus may have jumped the gun in defining a generational split between 3rd and 4th.
Indeed. So after I finished this analysis, I was left questioning whether or not the Fourth Generation should truly be classified as such.
However, there's been some good discussion in this thread, and one thing that struck me in particular was worldlove27 and @citron-icy's assertion that what sets the Fourth Generation apart is its groups' distinct focus on "Western" markets. That's a viewpoint that I hadn't really considered before, but it sort of makes sense.