Nope, there is no built-in standard solution for that.
Is it possible to build something like that? Sure.
You could e.g. build a ODATA service that you implement on all your instances.
Then all you've got to do is to call the service for every instance you want the users to be created.
But there is no way that you hook in to the execution of the standard SQL command (CREATE USER) and execute code based on that - let alone doing that in another system.
Up to now, SAP HANA integration is about data integration. What you're looking at is more application & process integration.