The ability to rename databases and collections is not currently something that is in our road map.
Currently the way to accomplish this task in Cosmos DB is to create a new collection with the changed name then use bulk exec or change feed to populate it.
Thanks for your request and input on this. We may consider this for a future planning cycle.
We now have a preview release of Bulk Executor Library 2.x with support for .NET Standard for available for review.
Download the latest preview version here. https://docs.microsoft.com/en-us/azure/cosmos-db/sql-api-sdk-bulk-executor-dot-net
And please provide feedback here,
Thank you.Anonymous commented
+1 for .Net Core