If SpaceX is responsible for any problems, it will look bad for their reliability. From another article:

The Zuma mission was originally supposed to launch in mid-November, but SpaceX stood down for a while to study data from payload-fairing test performed for another customer. (The payload fairing is the protective nose cone that encases a spacecraft during launch.)

https://www.space.com/38826-spacex-launches-secret-zuma-miss...