I’m not sure about the author, but I consider emacs essentially a modal editor. The vast majority of actions are preceded by a combination of modifier key presses, which is essentially modal, except you can’t (or can you?) keep it sticky.
So, for example, next line in Emacs is Ctrl+N whereas in Vim is Esc+J. The only difference in VIM is that you don’t need to hit ESC the next time want to go to the next line whereas Emacs reverts you to “insert” mode requiring you to press Ctrl again. But in both you can type out a number to allow you to jump 5 lines instead of just 1 with each key press.
Of course, those are only the in built modes. In many ways, emacs is even more modal than Vim, since there are so many packages that shift you into different custom modes With different behavior (e.g. org mode, magit, etc).
Org-mode and magit are modes in the sense that they are different environments, not input modes. You won't have a good time trying to update your calendar using magit, and reverting the latest commit is going to be a challenge from within org-mode. These are different tools.
I'd say once again, emacs can be as modal as you like, more or less exactly like vim, or it can be non-modal.
Simply create a bash source code block that goes in the right directory and does the git revert. \o/
I see what you're saying about Emacs's modes, but understand that that's a different meaning of "modes" than people common use when talking about editors. By the definition you gave, I couldn't really think of _any_ editor that's not modal in some way.