A lot of folks online seem sure that the axing of The Late Show is a case of CBS giving in to some demand by Donald Trump…and given some of the things CBS has done lately, that's an understandable suspicion. It could be that but the "financial decision" seems utterly credible to me. Colbert's show is expensive and even with it leading in the ratings of all late night shows, it's quite possible that CBS could put something else there that would be more profitable. Or at least thinks they can.
Networks have canceled profitable shows thinking that there's more cash to be made with something else. It's also not impossible that forces high up in Skydance Media, which is likely to merge with CBS/Paramount, don't like Colbert's politics (and recent criticisms of the "bribe") and decided to dump him without any pressure from the White House.
And of course, it's possible that there are more sinister doings here. One way I think we might know is if we see some of those Trump tweets where he basically confesses to his dirty dealings. A more likely way would be to see what Jon Stewart has to say. I don't believe we've heard from him yet but he has a very real interest in this. Colbert has ten more months of shows on CBS and may want to not get into too great a pissing contest with the network…for his staff's benefit if not his own. But Stewart doesn't have to get along with CBS until next May.