To be fair to it the article's job is purely to discuss the media's role in this and not the possible reasons for the coup as you're discussing. However, it is interesting to think of the breadth Chilcott will cover. Will the media's conduct in whipping up support for the war be condemned in it? If so then there's a mutual benefit to both Blairites and the media, particulaly the BBC, to get Corbyn out before Chilcott is published. Add to that the fact the BBC news is edited by a former Murdoch hack (as mentioned in the MediaLens piece) that relationship becomes more beneficial because both the BBC and Murdoch press were overall pro war.
The media's propagandizing for the war was certainly despicable, but not actually criminal. The report might condemn them, but they won't care about that, they're some distance beyond shame. They'll just blame the politicians for lying to them. The politicians, however, have the very real prospect of prosecution to fear.
Having said that, they're all in it together finally. Most of the leading politicians and media commentators have known each other since public school. It is indeed pleasant to think that the report may condemn the entire corrupt crony cabal culture that they represent.