Cloud based architecture just means that the software architecture is built from the beginning to run on the modern cloud. I'm this case architecture means the structure of the software, not cloud servers as a whole. "Hyper-converged infrastructure" sounds like corporate jibber jabber to just say whatever their infrastructure (servers and networks) is that it'll just be well connected with itself and the service. I agree there's nothing to directly imply they're making their own cloud solutions like AWS. There would be a lot more server details and details about hardware or such that is not present. Most cloud systems, even the small ones, have in house controllable load balancing or other stuff like that.