Why does 'pkg install -A xx' reinstall pkg?

[Yuri]

I saw it many times how 'pkg install -A xx' reinstalls pkg:

> Installed packages to be REINSTALLED:

>        pkg-1.21.3




It doesn't explain the reason.


Why is such operation ever needed?


The package version doesn't change, and there are no dependencies that 
change, so why does it need to reinstall pkg?



Thanks,

Yuri