Deadline retracts/corrects a story they helped blow up earlier today. 20th Century Fox is still going to be 20th Century Fox in all consumer-facing ways. "21st Century Fox" is just a name for the new umbrella corporation that envelops all of News Corp's being-spun-off media properties.
This, the latest choice from the company that decided to launch a new cable channel called FXX when they already have one called FX. No one will get confused, I'm sure.
The title of this post references the 1953 merger of 20th Century Pictures and the Fox Film Corporation, where the new company's name featured a hyphen for some years as "20th Century-Fox".