Onboarding Narrator button doesn't update upon pressing Ctrl+B

The bug

The Narrator button on the onboarding screen doesn't update when the Narrator setting is toggled using Ctrl+B.

This affects the onboarding screen only. In Chat Settings and Accessibility Settings, pressing Ctrl+B correctly updates the Narrator button.

How to reproduce

1. Launch a new Minecraft installation
2. Press Ctrl+B on the onboarding screen
   → The toast "Narrates All" is shown
   → The Narrator button still says "Narrator: OFF"

Expected behaviour

The Narrator button on the onboarding screen should always reflect the current state of the Narrator setting, as is observed within the options menu.