Just like you can end meetings early in Outlook for Windows, you will soon be able to start meetings late. The Microsoft 365 Roadmap entry suggests that the feature is currently in development, and it will go live for all Windows desktop clients in December 2020.
Once it finally arrives on Outlook on your PC, the feature will bring the ability to opt for meetings and appointments to start 0 -15 mins after the specified time. Outlook users will be able to enable it in their Calendar settings.
Overall, the new feature seems to be a welcome addition for people who are often stuck in back-to-back meetings and want some breathing room. This setting will make it easier for them to leave meeting rooms and be in good time for their next appointment. However, there’s still room for improvement.
Outlook for Windows still doesn't allow users to automatically block the next 15 minutes after a meeting. If you want this to change, be sure to provide your feedback on the Outlook UserVoice website.