So, here are a few links that I was able to. These are old because they were from the old days.
- Jeff’s dive rant
Overwatch Forums - tier distribution post
Competitive Mode Tier Distribution - an interview with Fran from this year where he repeats the general idea that dive wasn’t played in lower ranks.
https://www.reddit.com/r/Competitiveoverwatch/comments/ae21h8/jeff_kaplan_destroys_plat_and_below/
That’s all I could find.