The article itself is basically an empty assertion.
Colbert was bought and paid for by corporate media and he has now outlived his usefulness to them.
They kept him around for so long because he didn't seem to have any issues with pushing capitalist propaganda regardless of how it hurts people.
What really got me was his disinformation campaign about vaping. The science was already out at that point and he ignored it because he was told to ignore it.
This is just one example.