Yes, a kid like this needs challenge at school. But the part that seems to me to tip the balance toward pursuing a diagnosis is not being able to follow through on household tasks-- tooth brushing, getting PJs on-- without multiple prompts.

The child sounds able to do these simple tasks, and yet isn't getting them done, although it would be age appropriate to be able to do them independently. That combined with the school issues suggests something more than needing challenging work.

My two cents, YMMV,
DeeDee