This seems like a very obvious thing to have in the settings. I’ve recently updated my site without knowing this was pushed and after one day I’ve already seen the [grid] text show up in posts because people don’t have the technical understanding of what it’s doing or what it means. I’ve also received a complaint that it’s automatic.
The grid in our toolbar is Masonry Image Gallery, which I think works better generally because it doesn’t crop the image (but there are a few cases where [grid] is preferred). So having [grid] show up now is confusing.