CBC news (canadian outlet) released an investigation on this yesterday, and found:

> While the facility was functioning as a school, CBC News has confirmed a previous New York Times report stating the building was once part of an Islamic Revolutionary Guard Corps (IRGC) base.

https://www.cbc.ca/news/world/iran-school-bombing-investigat...

Assuming AI was used for finding targets, perhaps the training data was out of date?