Text predictions enable a faster typing experience, and Microsoft Word has had the feature since last year. However, it wasn't available across all platforms, which is something Microsoft is looking to change by expanding its availability to more platforms.
According to Microsoft 365 Roadmap page, Microsoft is now working on a feature for Word on Mac that will predict the text as you type on the editor. Mac users will be able to write more efficiently with the text predictions capability as they will save a lot of time.
Although not confirmed in the Roadmap page, it will be very similar to how text predictions work on Word for web, Windows, and Android. If you disagree with what Microsoft has predicted, you can continue to type, and the prediction will disappear automatically from the editor. And to use the predicted Word or phrase, you'll need to press the Tab key on your keyboard.
Microsoft is using Machine Learning mode to make suggestions based on the text you type, making typing a lot faster and allowing fewer typing errors. As per the Microsoft 365 Roadmap, Mac users will get predictions on Word in September. Office Insiders in the Current Channel will likely get it before it being rolled out to the general public.
For Mac users, it should not surprise you if Microsoft doesn't keep its promise of making text predictions available in September. We may see a repeat of what happened to dark mode for Word Web — it was supposed to come in May, but hasn't materialized yet.
Source: Microsoft 365 Roadmap