Can you show us the UI of your OneNote?
Besides, please go to File > Account > Product Information
, check and tell us the version name and version number.
Please note, the visual refresh or new feature be turned on using the Coming Soon feature is rolled out in stages, and randomly to Office that meets the requirements. For more, please refer to 'Don’t have it yet? It’s probably us, not you.'
In addition, Coming Soon option IS NOT always available in Office apps. It is designed to share significant changes that will soon roll out to Microsoft 365 subscribers. The megaphone button and on/off toggle not be visible once those updates are fully rolled out to production and will appear again only when Microsoft plans to introduce additional, material changes in Office apps for Windows.
Thanks for your understanding.
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