Are the style guides updated to reflect the public use of these words? If so, I imagine if we were to graph the change in use over time in the public would be a much more gradual and organic one?
Style guides generally update to represent the editorial team's preferences, to reflect changes in the wider world (e.g. see the comment in this thread about "Constaninople"→"Istanbul", or to make a point (see the New Yorker's continued use of diaresis in coöperation etc.[1])
[1]: https://en.wikipedia.org/wiki/Diaeresis_%28diacritic%29#Engl...