It has been possible to reschedule appointments with others via the actual appointment for some time. Rescheduling required users to go into calendar, open and edit the appointment there even if you know you can’t make it. An update coming to the G-Suite web interface will change that very soon.
When you open a Google Calendar invite in Gmail, you’ll see a new “More Options” dropdown menu, allowing you to propose a new time for the meeting or add a note to your RSVP. Selecting either option will open the respective event section in calendar.google.com, where you can make those updates directly.
It’s another welcome development from the team at Google that makes not just time use, but time scheduling far more efficient for users.
The rollout has begun for Rapid Release Domains (this is a choice your G Suite Administrator can make) across the coming 2 weeks and Scheduled Release domains will see the update starting January 6th 2020.