Office 365 message traces: Is there a limitation of the Splunk add-on, or from Microsoft?

[bdaugustine]

While browsing the documentation for the "Splunk Add-on for Microsoft Office 365", I see a statement:

"The MessageTrace API for the Splunk Add-on for Microsoft Office 365 does not support data collection for USGovGCC and USGovGCCHigh endpoints."

(https://docs.splunk.com/Documentation/AddOns/released/MSO365/Configureinputmessagetrace)

Is this a limitation of the Splunk add-on, or from Microsoft? Being USGovGCC, it would certainly be nice to have message traces...