Would be good if this could be done.
There’s a full simple to understand tutorial here:
Tutorial - Develop a SCIM endpoint for user provisioning to apps from Azure Active Directory | Microsoft Docs
They even provide a sample implementation with guidance. It’s in C#, which is what Bitwarden uses for server-side anyway:
Build a SCIM endpoint for user provisioning to apps from Azure Active Directory | Microsoft Docs
GitHub - AzureAD/SCIMReferenceCode: Reference code to build a SCIM endpoint to automate provisioning
The crux of the features required for SCIM are already available in the Bitwarden Public API anyway, so, this seems to be just a matter of using the sample code above to adapt in a way that conforms to SCIM standard.
Would really love to see this implemented. That way, all the user provisioning could just be done without any on premises software, Okta or AzureAD could just take care of it in the cloud!