Yes and no; base R is extremely stable, but if you need to install dplyr, maggrittr, ggplot2, Rcpp and knitr/rmarkdown to reproduce a large fraction of the work

Yes and no; base R is extremely stable, but if you need to install dplyr, maggrittr, ggplot2, Rcpp and knitr/rmarkdown to reproduce a large fraction of the work that's been done in the last few years that seems somewhat equivalent to language evolution. But with rough edges, because some of the nice workflows that this opens up (say piping) are not necessarily in line with the way R wants to deal with objects. In my experience, Julia is uninteresting to most statisticians because of the lack of mature libraries and because R is already good enough for most of the stuff they want to do. I don't think that relatively small language changes like the one discussed in the original issue are even on their radar, and I doubt that these changes are driving away people that would otherwise be maintaining packages.