From Daily Beast, how Colbert learned of Kimmel's suspension.
From DailyBeast
Colbert Learned Kimmel’s Fate in Front of Live Audience
Stephen Colbert was almost done taping The Late Show Wednesday night when audience members reportedly watched him learn the news that ABC had suspended Jimmy Kimmel following threats from Trump FCC Chair Brendan Carr in real time.
Spectators at the taping have said that Colbert "appeared visibly shaken" as he read the news on a phone that someone handed him during a commercial break, “raising his hand to his mouth in disbelief” before leaving the stage for several minutes. When he came back to record the show’s final segment, he promised the audience that he would address the news on Thursday’s show, which will feature Kimmel’s close friend, CNN anchor Jake Tapper, and New Yorker editor David Remnick as guests. Colbert, whose late-night show was canceled by CBS after he called out the Trump administration’s “big, fat bribe” to the network, did not mention Kimmel during Wednesday night’s broadcast.
A representative for Bill Maher also confirmed to The Daily Beast that he plans to address the Kimmel situation on HBO’s Real Time Friday night.