I think it's an excellent model and it's one you're going to be seeing more of. It's called a model of decentralization, in which all the data isn't housed in one central database that different arms of government can access. The problem with centralization is that it is subject to far greater risk in terms of data breaches, privacy infractions, unauthorized access to the data by curious employees, inside jobs and all of that. All of the data is placed at far greater risk if it's in one central location.
You may recall about six months ago that Tim Berners-Lee, who created the World Wide Web, was aghast and said he was horrified at what he'd created because it is a centralized model that everyone can basically break into more easily and access everyone's data in an unauthorized manner. Centralization also lends itself to surveillance and tracking of citizens' activities and movements. It is fraught with problems from a privacy and security perspective.
In Estonia, the decentralized model is superior, with different pots of information. Each database contains information that can be accessed for a particular purpose. Often that's referred to as the primary purpose of the data collection, and individuals within the government are limited as to the uses of the data. They have to use the data for the intended purposes. The more you have decentralized pots of information the greater the likelihood the data will remain and will be retained for the purposes intended and not used across the board for a variety of purposes that were never contemplated.
You have far greater control and people, citizens, can be assured of a greater level of privacy and security associated with that data. It's a model that is proliferating and you're going to see much more of it in the future. It doesn't mean that other arms of government can't access it. They just can't automatically access it and do whatever they want with it.