When Boston Ballet saw its annual “Nutcracker” production forced out of its longtime home in the city’s Wang Theatre, many observers wondered if the company could survive in a new, smaller home. But artistically, at least, “Wang inadvertently [did] Boston Ballet and its audience a favor. As impressive as its technical wizardry and, of course, always terrific dancing were, the company’s Wang-sized “Nutcracker” had, over the years, started to look more and more remote… But for the [new, scaled-back] production, artistic director Mikko Nissinen has prepared the kind of fresh, coherent staging and (mostly) new choreography Boston Ballet’s “Nutcracker” has needed for a long time.”