Work hours setup in Outlook are seen in Teams when setting up a new meeting

Star-D yes, it would be impossible Teams to know the availability of someone outside your organisation as the privacy settings prevent that.

However, it should not be difficult for Microsoft to ensure that Teams shows people's work hours for people inside your organisation as this feature is already available in Outlook. The issue is why this is not available in Teams (for those of us who do not use Outlook)!