Kevin Costner, other cast members from Yellowstone, and series creator Taylor Sheridan were all notably absent from a Saturday event at PaleyFest, where Costner, 68, and his castmates were scheduled to participate in a panel about the series during an episode screening.
The panel took place following a Deadline report that Matthew McConaughey was in talks to star in a spinoff of the popular Paramount+ series, as Costner considered an exit to instead focus on directing and starring in the upcoming Western, Horizon.
The event — which took place at the Dolby Theater in Hollywood — initially promised that Sheridan, EP David Glasser, Costner, Kelly Reilly, Cole Hauser, Luke Grimes, Kelsey Asbille, Wes Bentley, Gil Birmingham and Jacki Weaver would all be part of the panel. However, the final panel lineup featured Josh Lucas, Dawn Olivieri, Wendy Moniz and Mo Brings Plenty.
Keith Cox, the president of development & production for Paramount Network, said at the event that he was hopeful of Costner's continuation on the show, but he was unable to provide a specific update on when production on Season 5 might resume.
"What I can say is our star, the face of our show and the executive producer, are very confident he's going to continue with our show," he said, prompting a round of applause.
Reps for both the Paley Center and Paramount Network did not immediately respond to PEOPLE's request for comment.
When asked at PaleyFest if he thinks the show could continue in a world without Costner's character, Lucas — who plays Costner's character John Dutton in flashback — said that he thinks Sheridan has "always planned on at some point, having Kevin die and having multiple characters die."
"And so you know that that's just the way the story… the evolution of what the ranch is. That's why when you see the cemetery and you see the names of Elsa and you see the names of Jacob and you see these names, I think it's of course going to evolve and change," Lucas, 51, says. "And I think that's what hopefully people will really like as it goes. I don't know, Taylor can tell a story about the future for all we know."
At the PaleyFest panel, fans in attendance were also surprised by the last-minute lineup change, with guests trickling out as soon as they learned of the panel shake-up, according to an attendee Another attendee claimed there were no refunds, even with the trimmed-down panel, Variety reported.
A spokesperson for Paramount Network previously told PEOPLE in February that they hoped to have both McConaughey, 53, and Costner be part of the Yellowstone family. "Kevin Costner is a big part of Yellowstone, and we hope that's the case for a long time to come."
Since then, McConaughey's involvement in a spin-off of the popular Paramount+ series was revealed to be moving forward by ViacomCBS President Chris McCarthy. That series will be the latest spin-off inspired by the series — preceded by the prequel 1883 starring Tim McGraw and Faith Hill; the Helen Mirren and Harrison Ford-led prequel, 1923; and 6666.
McCarthy also told THR that the franchise "wouldn't be what it is today without Kevin and we hope that that stays for a long time to come."
