Hi Krishnan N •,
Welcome to Microsoft Q&A forum.
As I understand, you want to know the supportability and workaround available for "serverstatus" diagnostic command in Azure Cosmos MongoDB.
Since this command is yet not supported as per the standard document, we recommend you to raise feedback over Azure Cosmos DB Feedback channel so that team can work on the feature depending on the importance and up-votes.
As part of getting details related to performance metrics, you can refer to:
https://learn.microsoft.com/en-us/azure/cosmos-db/use-metrics
Refer to the document for Azure Cosmos MongoDB:
Apart from Azure Monitor, you can use third party monitoring solutions to monitor your Azure Cosmos DB instances.
https://learn.microsoft.com/en-us/azure/cosmos-db/monitoring-solutions
Let us know if this helps.
Thanks.