DirecTV RedZone and NFL Network RedZone are two separate programs, independently produced.
The DirecTV version has been around for many years as part of the Sunday Ticket "Superfan" premium package. Two years ago, when NFL Network took the concept to basic cable, DirecTV dropped the "Superfan" add on and made their RedZone standard for all subscribers.
DirecTV used to have a MLB version of RedZone called StrikeZone (or something similar). Same gimmick....every run from every game. They only ran it on Tuesdays, Wednesdays, Fridays, or basically the days that there was always a full slate of games. If I recall, when MLB Network came to be, they forced DirecTV to stop the channel (because MLB Network basically does the same gimmick from 7-11 every night).