That doesn’t really explain the cited use of the term in 1986, though, if the term was invented in 1987 as has been claimed. The “Chris Evert’s bracelet broke at the US Open in 1987” story, while it appears all over the Internet, always traces back to the same source - Diamond Blog - which makes it highly suspicious. There would be other primary sources if a story like that, involving a high profile athlete, were true. that doesn’t mean Evert didn’t have her bracelet break during the '87 Open, but clearly that incident did not result in the invention of the term.
The more prosaic, and likelier, explanation is simply that it became fashionable for tennis players to wear diamond bracelets in the 1980s, and so the name started being used.
It certainly does seem to be a 1980s term, though. That surprises me, but then, a lot of terms become so common that you assume they’ve been around forever. If you ask a hundred people when “Murphy’s Law” entered the language they’d probably all say it predates their birth by generations, but there is no evidence of the term existing prior to 1952 and most people wouldn’t have heard of it until the 1970s. (The general concept’s old, but that name for it is not.)