I like how the author try to make you understand the difference between collecting data and curating knowledge. But unfortunately, this concept of acquisition of data is really personnal and often we mix our own interest and the pertinence of the data for the students. Strangely, it's how start hoarding!
It is true that we need to have useful and pertinent data for our students. I guess the big difference between collecting and curating for me is the "useful" concept. Data given to students should engaged them in the road of knowledge and not bury them under a mass of information (if you want to lose a student, it is the best way).
I have to say that personaly, it is hard to make the difference between hoarding and curating; I still have the notebook I used in grade 1! I am collecting information on everything that cross my path. So this year I started a classification, the same way that the author is doing, but with my own criteria. First by subject, second by level, and third on the pertinence of the information (it is useful, can it be use in an activity? A demo? An article? Which level of Bloom's taxonomy? Etc...)
This classifications my own way to curate information and make sense in my hoarding!
I guess, to do so, we have to put our own interest and desire on the side most of the time to be able to focus on the need of our students. To find the fragile balance between what they need to know and what can interest them. It is not an easy goal.