They didn't call it out as a concern, they said at the beginning of the section "Halloween Problem is a database error that a database system developer needs to

They didn't call it out as a concern, they said at the beginning of the section "Halloween Problem is a database error that a database system developer needs to be aware of." To be honest, just like you I also thought that it was related to PostgreSQL or other popular SQL databases somehow, until I re-read the section multiple times.