It can integrate with on premise solutions through hybrid media services (this is current not future), but I don't believe there are any plans to give it the ability to register to CUCM/Expressway. Doing so would eliminate the interactive whiteboard capability, BFCP is just one way sharing. That would make the Spark Board just a video device.
Here is more info on Spark hybrid services, I think this is what you're referring to but it is not new/future, this has been available well over a year.
https://www.cisco.com/c/en/us/solutions/collaboration/spark-hybrid-services/index.html
