SmackDown will remain two hours!
Starting on Friday October 4th, WWE's SmackDown brand will officially be on FOX and today, FOX released their 2019-2020 Fall prime time schedule and it is listed on that schedule that SmackDown will continue filling the 8 PM EST to 10 PM EST slots.
8:00-9:00 PM 9-1-1
9:00-10:00 PM Prodigal Son
8:00-9:00 PM The Resident
9:00-10:00 PM Empire
8:00-9:00 PM The Masked Singer
9:00-10:00 PM Not Just Me
7:30-8:00 PM ET Thursday Night Football Pregame Show
4:30-5:00 PM PT 8:00 PM-CC ET/5:00 PM-CC PT NFL Football
8:00-10:00 PM WWE’S Smackdown Live
7:00-10:30 PM Fox Sports Saturday: Fox College Football
7:00-7:30 PM NFL on Fox
7:30-8:00 PM The OT / Fox Encores
8:00-8:30 PM The Simpsons
8:30-9:00 PM Bless the Harts (new series)
9:00-9:30 PM Bob’s Burgers
9:30-10:00 PM Family Guy
Prior to this announcement, the current WWE Champion Kofi Kingston commented on the rumors of SmackDown possibly being three hours on FOX and Kofi is looking to be champion by the time the FOX era begins but he must first defeat Kevin Owens at Money In The Bank to retain the WWE Title.