I know of a couple individual cases of that. This is from when I was a kid, but I bet it still goes on today.
Officially naming the new baby for a grandparent / aunt / uncle wasn’t something their ethnic or religious background demanded, but it was sure expected by either Dad’s or Mom’s extended family for … reasons. To which the other parent assented only if the kid would be known by an unrelated nickname.
Naming kids for grandparents or equivalent generation relatives would drive a sort of ping-pong effect where the same names became common or rare in alternating generations.
You did bring some actual cites to the thread, and thank you for that. The shear variety of names available today and the fact that just a handful of names no longer dominate the stats strongly suggests that nicknames aren’t as necessary to disambiguate classmates, teammates, etc., nor do parents have as much motivation to do as I outlined above.
Maybe like kids walking to school on their own, there’s a critical mass where above that point nearly everyone does it, and below another critical level, nearly no one does. Most everyone wants to be in / near wherever the herd is.
Last fall, I had four students in one class who were all listed on the roster as “Elizabeth”, but they went by “Elizabeth”, “Lizzy”, “Eliza”, and “Ellie”. Plus another who was listed as “Elise”.
I think they each came up with their preferred name independently, but it was still very convenient that “Elizabeth” has so many nicknames.
Going through grade school mumble years ago I was one of 3 with my given name. A name with no standard nicknames whatsoever. Same story every year from K to 6th when we entered middle school and no longer shared every class all day long. None of the three of us had a family history of a nickname so we just got used to being known as “'FirstName LastInitial”. And no, our shared name was not an especially common baby name for our year cohort. Just a random clustering of random data.
We also had 4 girls along with us all those years who shared variant spellings of Susan / Suzanne / I forget. 4 distinct spellings, but only 3 distinct pronunciations. “Susan” was not an especially common baby name for our year cohort either.
I’m sure our teachers were glad when our coed cohort of coincidences promoted to the next grade.