"Reading in class" can cover a lot of ground, the whole range between "we used it as a textbook for an entire month" and "a student brought it in for the 'teacher reads your favorite book aloud at circle time' award".

Given the kind of books they are, my guess (if the teacher hasn't just completely checked out after last year, which is possible!) they're being used as some kind of enrichment, not as the main lesson plan. But who knows.