I don't know about those radio tabs specifically, but your intuition is correct. Many of the ARIA APG (component)patterns require JavaScript to update tab index and ARIA properties for full implementation. Focus management and key-control are two problem spaces that are common across many patterns and require JavaScript.

Focus management:

Focus scopes and restoring focus requires JavaScript. Complex UI components like combo box, grids, and trees require dynamically adjusting tab index and focus. Combo Box requires managing accessibility tree focus separately from DOM focus. Modals implementing focus scopes and restoring focus scopes requires JavaScript.

Key controls:

The ARIA APG patterns call for differences in tab and arrow key control from what the browser would supply. Patterns that involve list of groups use tab to navigate between groups and arrows to navigate within groups.