"pkg upgrade foo" installs foo if not already installed, bug?

Observe the following:

    $ pkg info|grep -q cowsay && echo installed || echo not installed
    not installed
    $ sudo pkg upgrade -q -y cowsay
    $ pkg info|grep -q cowsay && echo installed || echo not installed
    installed

It looks like when "pkg upgrade" is given an uninstalled package to
upgrade, it installs it.

(This is on 13.1-RELEASE.)

I would think the expected behavior would be to throw an error because the
package does not exist, or at least have a switch to control it.

Am I misunderstanding how "pkg upgrade" should work, or was this
behavior changed recently?

(I quickly looked through bugzilla, the pkg src tree, and the GitHub
issues for pkg and didn't find anything, but it's possible I may have
missed something.)