Great article. I'm from the generation that had a mix of the old and new(early 90s). I find that most of us born in the early 90s and very late 80s often identify with each other. Childhood memories, interests and all that. I got to play outside and also enjoy the tech side.
The number of generations will keep increasing because everybody has a new struggle and no matter how silly it sounds, there will be people that identify with it
I think your explanation is the one that's right; that "generation" today, has more connotations than in the past, when, at least the public understanding defined it mainly as being related to a span of years.
What I don't understand, is whether the acceptance of "generations" being related to designs, activities and/or trains of thought, still allows for the standard "generation" that refers to a span of years.
I think that rationale has been either made obsolete or buried under a pile of "generational definitions" that it becomes only a nuance in principle.
What I deduce from people I interact with is that modern generations are defined by similarity of struggle and preference. The classical time-dependent definition is embedded somewhere in all the new subjective definitions