Fox pushed back Monarch's premiere to the fall due to not only the pandemic, but because of creative changes

Deadline

“We’ve completed about five episodes, but when we made the showrunner change, there were some creative changes that were coming along with it that we’re implementing into the episodes that are really exciting,” Fox Entertainment president Michael Thorn told Deadline of deciding not to have the country music dynasty drama premiere after the Jan. 30 NFC Championship Game. “We want to ensure that we’re able to do it and give our partners the time to implement them, so it’s all born out of setting the show up for success, and we’re really excited about it”