Late launch is a factor of everything that has been done to that point.
Starting with strength, body type, coordination, stability, mobility. To be able to flex the trunk and stabilize the front leg in a fashion such as Chapman you have to have excellent ankle-knee-hip-glute strength and mobility.
To have any chance to get to this point, you have to move your center of mass efficiently (tempo), and understand the connection-disconnection sequence around the spine.
The late launch is also important because it starts a healthy declaration pattern as well.