https://www.techradar.com/news/google-is-now-rolling-out-confidential-mode-and-smart-compose-for-gmail

If you've opted into the recent Gmail update, two new features will soon be rolling into your inbox: Confidential Mode and Smart Compose. If you haven't already switched to the new design, here's how to do it.

Confidential Mode was originally due to arrive at the same time as the overall redesign, but was delayed (for confidential reasons, presumably).