Chris Everet was playing tennis with the bracelet earlier than 1987. Such an incident (1987 match) of having it break and pausing a game and tv coverage to find the diamonds can easily explain the sudden spread of the term.
It may have been used… it might have gotten a blurb, but the very person who was known for wearing such a bracelet is suddenly on TV looking for its diamonds. I doubt the bracelet had anything even close to that sort of coverage prior to that.
1987: the bracelet’s name was forever linked to tennis, thanks to Chris Everet, who had been wearing one up to that point, but suddenly drew national attention to it.