Google has already begun rolling out the update for personal and domain users in February, and the change will reach all Gmail users in April. You can expect to see notification bubbles for chats and spaces, and you’ll be able to reply to those messages in a full pop-up window. Google apps will be accessible in a collapsible menu whether the pane is open or closed. Additionally, you’ll no longer have to click multiple tabs or open new windows to join meetings or use other features.
Though this will become the default user view in April, for a limited time, you can opt out and revert back to the classic Gmail experience. By June, you won’t be able to opt out of the new layout as it will become the standard for all users. The change affects Gmail users with personal and business accounts with the exception of Google Workspace Essentials customers.