I mean, it's mostly training for the priests for how to react when people go to them for help. It's said in the article, the near totality of "possession" people report to their priest is just some normal human think, be it hyperactivity, depression, PTSD, etc... So I guess it would probably teach the priest how to identify such behaviour and help the family to contact medical specialists.

The Catholic church have a whole analysis method for classifying alleged miracles from "Nah, it's just normal human thing. Don't worry." to "Lemme call my boss, this is NOT supposed to happen!" or "Honestly, idk, seems legit. Unusual but legit." Seems only logical for them to do the same with possessions.