No, children under 16 (under 18 in Scotland) will continue to claim DLA in the way that they do now. At age 16/18, they will have to put in a claim for PIP.
The DWP/Social Security Scotland (SSS) will write to children in receipt of DLA when they are approaching their 16/18th birthday to explain about claiming PIP. Shortly after your child turns 16/18, the DWP/SSS will write to them inviting them to claim PIP. It is very important to make the claim by the date given in the letter so that DLA can continue until the PIP claim is decided.