Apologies if I'm missing something but it looks like ggplot2 has not been updated on cran for ages.
The version on CRAN is 2.2.1, pub date 2016-12-30
As a result, CRAN is out of sync with the ggplot2 documentation: http://ggplot2.tidyverse.org/reference/ggsf.html
I see a solution here:
But I would like to know when ggplot2 will go to CRAN?