In my opinion what we see with these teachers is a kind of turn of the screw of Foucaultian power. It is the exertion of power at a meta-level which denies that which it is. In a sense this meta-power-power gives even less scope for the individual liberty to criticize it, than does simple authoritarian power. Ultimately the new power is one which does not recognize itself as power, and will not accept a critique of itself as power, yet wants, as the conservatives [David Thompson and commenters on his post] do effectively point out, particular outcomes.
In that sense the "spontaneously correct" responses that the children came up with after their play had been pedagogically guided, are in some sense related to Foucault's "confessionalism" in modern regimes of power and knowledge.
It is not anymore a simple opposition of spontaneity versus discipline, as in some ham-handed authoritarianism. It is a meta-attempt to discipline the very spontaneity of the children themselves, to "structure" it for outcomes. To "get them to find the right answers by themselves," but the answers are still predetermined, not a matter of free inquiry.
In an earlier draft of the essay, I compared the Legotown teachers' indoctrination to the worst of Catholic school, but on reading humbition's comments, I realize that analogy is inapt. However heavy- or light-handed Catholic school indoctrination might be, the authority of the priests and nuns is never in doubt. This authority might be granted on unfalsifiable, irrational terms, but it is overt and admitted.
The indoctrination by means of the non-authority authority the teachers employ is far more corrosive than even the very worst the Catholics can do. An 8-year-old at least has a fighting chance against Catholic school; the authors and their ilk have fooled the editors of a published journal, half the philosophical community and even to some extent their critics; what chance does a child have?
An analogy springs immediately to mind: The number of Ph.D.-level academics who take this blanket anti-authoritarian stance: If they're so anti-authoritarian, why are they seeking the authority of degrees, appointments and tenure?
I am suspicious of anyone who styles himself anarchist who does not first and always—as I do by titling this blog "The Barefoot Bum"—find some way to undermine his own authority.