Whilst I must admit I've never heard of the term "managed out" (apparently, called "counselling out" in the USA) before, I think most people are aware of the practice of "weeding out workers who are either not up to the job or are the wrong person for the post."
The subject of managing out is the basis for a very interesting article by Michelle McGinty of The Scotsman - Encouragement to leave the job?
I'm not quite sure if a particular high-profile event or survey led to the article in question. What's good about the article is how a range of views are called upon, i.e. CBI, TUC, employment lawyers, etc.
Probably most notable of all are the comments left by readers. By the comments alone, it would suggest more people have been managed out of their jobs than the CBI or employment lawyers care to acknowledge.