https://techcrunch.com/2022/06/29/gmails-redesigned-interface-including-chat-and-meet-is-now-the-new-default/

Gmail is now rolling out a new user interface that will show Chat and Meet sections in the side pane by default. Google introduced this new integrated view earlier this year through opt-in options, so you had to manually enable Chat and Meet panes. However, as the new phase of the rollout is starting, the company will force you to opt out if you want the classic Gmail view.

Google says the change is rolling out to Google Workspace customers and users with personal Google accounts alike. This includes Google Workspace Business Starter, Business Standard, Business Plus, Enterprise Essentials, Enterprise Standard, Enterprise Plus, Education Fundamentals, Education Plus, Frontline, and Nonprofits, as well as G Suite Basic and Business customers, and Google Workspace Individual users.