I was reading Git v2.9.1's release notes and one of the changes reads:
"git status" used to say "working directory" when it meant "working tree".
This was done to improve consistency and avoid ambiguity. As explained in the commit that changed this behavior:
Working directory can be easily confused with the current directory.
So this change was made to better disambiguate between the working tree, meaning the location where your repository has been checked out, and a the current working directory where you are running the
git status command, wich may be somewhere beneath your working tree (or perhaps not, if you set
GIT_WORK_TREE environment variable).