Yes, you can control this on a per-user basis via the ExternalAccessPolicy controls. Here's an example from the official documentation: https://learn.microsoft.com/en-us/microsoftteams/manage-external-access#limit-external-access-to-specific-people
Disable External MS Teams Chat for specific user only
Please i need your help on this.
Is there a way to disable external chat (sending/receiving) for 1 user only , even though external chat is enabled in tenant level.