A family of Microsoft word processing software products for creating web, email, and print documents.
Hi nightearth,
Thank you for posting your question in this community. After I watched the YT video you shared above. I noticed that the Dictate feature that this video is referring to is a Dictate add-in and it an experiment project by Microsoft Garage program back to year 2017. With this add-in, it can support 29 spoke languages as video presented.
However, this add-in I no longer supported at the moment. Because it has integrated with the built-in Dictate feature into Office application. For your information: Dictate an add-in for Microsoft Office on Windows.
Unfortunately, the built-in Dictate feature in Office application only support the following language at this moment. Some of the languages are removed from the Official released version. Probably, the product team would like to provide a stable user experiences in this feature. However, they are working to add more languages. Sorry for the inconvenience caused.
For your information:
Dictate your documents in Word – Spoken languages supported
Some users also noticed this limitation and raise an idea about MS office should support Arabic in dictation on Word UserVoice platform. If it is convenient, you can vote and subscribe this idea. As more as more users request this feature, the product team will aware this limitation and consider improving it in the future. Thank you for your understanding.
Best regards,
Dihao