I’ve met a Kyle who is exactly 50 this year.
I’m in that age group, and can’t really think of any, other than the famous examples.
Chad Everett, Adam West, Justin Hayward…
At least six of the above.
I know a Justin in his 50s.
My old drinking buddy Zach Tyler Adam Chad Ryan Evan Josh Chase Kyle Justin Dustin Smith.
My grandpa was named Justin. He was born in the nineteen teens.
For the United States … the Social Security Administration tracks baby names by popularity per decade … an interesting resource for questions like this …
And you have met both of these people? (Cf. the thread title.)
Of the names on the list, I only remember knowing some Adams back in the day and they’d all be 50 now. But I don’t remember meeting men with those names who were over 50 at the time I met them.
“Remember” is the key word here. I’m not good with names.
I realize this thread is about male names…but I’m 60, and whenever I go to one of my high school reunions, I notice that most of my female classmates have names with two syllables and five letters: Karen, Tracy, Laura, Susan, Linda, Julie, Nancy, Carol, Diane…
How would I know how old they were? 
I had a neighbor “Zachariah” who went by “Zach” does that count? He would be about 90 by now. And went to kindergarten with a “Tyler” who if he isn’t 50 yet will be in the next few months.
In fact, yes, all of those. I dated a Chad who would be 52 now. There are Adams all over the place, and every 30-year-old bachelor in the 70’s was called “Dusty” for short.
The only one I might have to say “no” to is “Chase” because every Chase I’ve known was a Junior, and called that to differentiate him from a father called Chuck or Charles.
Yes on Justin, Kyle, and Josh.
Justin - now age 66.
One of my best friends growing up is named Kyle. We will be 51 this year.
Another friend had a sister named Kyle who is probably 55.
Kyle Rote was a NY Giant and a pretty well known name in the area. His son Kyle Rote Jr was one of the best known soccer players in the US when we all started playing. The name didn’t seem unusual.
Not for people under 50. They’re considered very old-fashioned.
I’m a Kyle, and I’m over 50. I’ve known people my age with all those names, except maybe “Chase”.
“Adam”? When the hell has “Adam” ever been an unusual name?
I’m 31. Throughout my life I have never met anyone named Adam who was my parents’ age or older. It’s very common in my generation, but seems to be very rare in previous ones, at least in the 20th century. (It may have been far more common in earlier centuries.)
The only older Adams I can even think of off the top of my head are Adam West (now deceased) and Adam Baldwin. Oh, and Adam Clayton Powell, who I’ve read about in the context of the Civil Rights movement. I have never MET anyone my parents’ age who was named Adam. And I have met a hell of a lot of people in my life.
As for Adam, I’m 42, and one of my dad’s good friends was Adam. Looking at my Facebook friends, I personally known 5 Adams, two are over 50, one is exactly my age, and two are about five years younger than me. There may be more I’m not thinking of, but that makes half the Adams I know 50 or over. It’s never occurred to me to be an 80s name or anything like that.
That said, at least in the US, the OP’s observations about Adam does appear to reflect reality in the US. And, come to think of it, the three Adams I know that are older were all born outside the US.