https://arstechnica.com/gadgets/2020/05/microsoft-plans-to-add-gmail-like-predictive-text-to-outlook-for-the-web/

Microsoft Outlook for the Web has the unenviable task of competing with a dominant Gmail—and much of Gmail's competitive advantage is thanks to ML-driven features like text prediction. But Microsoft is taking a step to face off directly with one of the features associated with modern Gmail—text prediction and completion.

In the past week, the company updated its publicly visible roadmap for Microsoft 365 features to include "Outlook on the Web - text predictions." The feature's description reads: "Using smart technology, Outlook will predict text while you type. Just use the Tab key to accept the text prediction." This suggests the feature would work very similarly to the way it does in Gmail.