As it stands the Microsoft Graph APIs offered for Teams Chats are currently in BETA, which means that these APIs are not supported by Microsoft and sudden changes are possible which can break the functionality completely or cause some disruptions in the backup frequency.

Even though availability depends on Microsoft's Graph API's, we still uphold our best effort to maintain backup frequency for Teams Chats backups.

Due to this we cannot guarantee SLAs on Teams Chats backups similar to what we offer with Mailbox/OneDrive/SharePoint backups.