The Legacy Reports in Cvent will be retired. As a part of the first milestone, you’ll no longer be able to create new saved Legacy Reports or access unsaved standard or custom Legacy Reports after Dec 15, 2020. Any events that are being copied via SOAP API after December 15th will not have access to Legacy Reports (including saved Legacy Reports that were in the event being copied from).
Any existing saved Legacy Reports will be available until June 30, 2021, at which point Legacy Reports and Parked Report Groups will be retired.
Any data you need access to should be available in the new Reports, but if you run into any issues, contact your Account Manager.