This references the deprecation of the Detailed Billing Report (DBR) from AWS that took place in July 2019.
Prior to July 2019, CloudHealth pulled all cost and usage data utilizing the DBR but AWS decided to retire this particular report and replace it with the Cost and Usage Report (CUR). CloudHealth has since shifted all reporting to using the CUR and this notification in the COST > STATEMENTS section is to let you know this change took place.
Your cost reports and statements should not be affected as long as you have the CUR configured correctly within the CloudHealth platform.
For information on configuring the CUR, see: https://help.cloudhealthtech.com/administration/aws/enable-cost-and-usage-report.html