Microsoft has recently switched on the feature to automatically add a Teams meeting to every new Outlook Calendar invite. This feature adds the Teams meeting link to the location and description fields in the invite.
If users have used any add-in to add a meeting invite, such as the RingCentral Scheduler add-in, then they will see the RingCentral meeting details also added to the location and description field.
Individual users can manually turn off this feature in their Outlook Web Settings, as shown in the image below.