Ben Brantley writes: “Rejoice, my theatergoing comrades. The children’s revolution has arrived on these shores, and it is even more glorious than we were promised. Rush now, barricade stormers of culture, to the Shubert Theater, and join the insurrection against tyranny, television, illiteracy, unjust punishment and impoverished imaginations, led by a 5-year-old La Pasionaria with a poker face and an off-the-charts I.Q. ‘Matilda the Musical,’ the London import that opened on Thursday night, is the most satisfying and subversive musical ever to come out of Britain, where it was nurtured into life by the Royal Shakespeare Company.”