Ahead of 9-1-1's Season 7 finale, Guzman shared his gratitude for the role of Eddie Diaz with Decider.
"Luckily I got a second chance, by the grace of God," the actor said.
"I know your spirit is still present, and your essence still lives on in the hearts of many," Guzman wrote.
Holker will be a judge alongside Jojo Siwa and Maksim Chmerkovskiy.
Lythgoe announced his departure from the show earlier this month following Paula Abdul's sexual assault allegations against the longtime judge.
"We all would have done anything we could to help him," DeGeneres said.
Holker honored her late husband with a post featuring pictures of herself and their children at his grave.
"I’m feeling this much pain because I’ve had so much love," Holker Boss said.
"He sold millions of albums, his life was music," one fan wrote.
Hall suggested tWitch died after the "pressure" he endured during Ellen DeGeneres' workplace scandal.