[win311fwg]

> The term "millennials" referred to a specific cohort of people that all share similar experiences

Exactly. That experience being coming of age at the turn of the millennium, with high school graduation being considered the milestone where one comes of age. Hence why Strauss and Howe called them millennials. While the people who were labelled millennials are no longer recent high school graduates, it is linguistically valid to remember them locked in that moment in time. High school graduation was the point of significance associated with the term.

> because they were born around a specific time (early ninties).

Easy to miscalculate, I suppose, but the cohort who graduated high school in the year 2000 were born in the early 80s.

"Millennial" did later evolve to be used where "Generation Y" was used previously. That represents a much larger age range — those born in the early 80s to mid-90s. Further evolution has seen millennial come to refer to those born in the latter half of the Generation Y, with "Xennial" showing up to refer to those in the earlier half. This might be where you had 90s kids in mind, but that is far from where the term originated. "Millennial" first appeared in 1987. Nobody was thinking about those born in the 90s at the time.