--docs flag doesn't do what the documentation claims

[iamdriz]

According to the documentation here: https://storybook.js.org/docs/react/writing-docs/build-documentation adding --docs to the start-storybook command will do the following:

• The top level item refers to the primary story for your component.
• Each individual story is now in a flattened display mode, with a different set of icons. This allows focus on the documentation itself.
• Storybook's layout is rendered differently. The toolbar will not be displayed.

However the toolbar is still visible and the tabs for both Canvas and Docs are shown.

Have I missed something? Or is the documentation for this feature out of date? The only way I could get it to properly disable the toolbar as per the documentation was to do the following on each Story:

previewTabs: {
      canvas: { hidden: true },
},

I'm running the latest version of Storybook 6.2.9