MigrationWiz no longer supports Teams private chat history as part of Mailbox migrations due to Microsoft's restriction on Teams data access through EWS.
For more information please review the following Microsoft-related article: EWS isn't supported when accessing Teams data.
We are currently developing a replacement feature utilizing updated APIs. However, we do not have an estimated time for the return of Teams Private Chat migration at this moment.
Important
Please note that Teams to Teams migrations (excluding Teams Private Chat) are supported as they utilize Microsoft Graph API.
Warning
Keep in mind that when "Teams Private chats" is selected for Microsoft 365 Mailbox migrations, the Not allowed to access Non IPM folder error is displayed.