Any child of compulsory attendance age who fails to attend school as provided in this chapter, or as required by the school board’s or school governing body’s attendance policy, or who fails to attend competent private instruction or independent private instruction under chapter 299A, without reasonable excuse for the absence, shall be deemed to be a truant. A finding that a child is truant, however, shall not by itself mean that the child is a child in need of assistance within the meaning of chapter 232 and shall not be the sole basis for a child in need of assistance petition.