Is your feature request related to a problem? Please describe.

As a user, I expect that I can navigate sites using the design system with my keyboard or assistive technology matching the visual order of the elements, so that I'm not confused or frustrated when trying to access parts of the page content.

As a developer, I expect that the design system incorporates accessibility best practices in its offerings, so that I am set up for success in implementing my web pages.

Describe the solution you'd like

One of:

• Remove order utility classes (note: breaking change)
• Keep order utility classes, but remove them from the documentation
• Keep order utility classes and document them, but include a warning message outlining the caveats of using them

Additional context

Related resources:

• MDN order: Accessibility concerns
• WCAG SC 1.3.2: Meaningful sequence
• WCAG Technique C27: Making the DOM order match the visual order

The order CSS style creates a disconnect between the visual and DOM order of the page, frequently causing confusion for users navigating the page with a keyboard or assistive technology, and potentially violating WCAG Success Criterion 1.3.2 "Meaningful Sequence".

In my personal experience, order is almost always misused, and I might worry that its presence in the design system could encourage (or at least not adequately discourage) inappropriate usage.

Related issues: #3920, #3526