Good, this is a good move. If a service cannot get its catalog under control and curated properly by the institutions that use it, then the service should be prohibited, especially to vulnerable children.

Libraries, including my municipal one, depend heavily on these eBook services, and the independent public libraries have basically abdicated their liberty and freedom to curate their collections and choose what readers can access. They have given that up to a commercial service that doesn't know or care about local communities nor their ethical or moral standards. So, I would support a widening ban for these services until they can restore said freedoms and liberties to libraries and educational institutions that finance their operations.