K-cup,
As a matter of fact, according to Rav Kook (Ein Ayah on masechet Shabbat 2:8) every movement that rises up has some part in Truth. However, there is also much falsehood. The task of chachamim in every generation is to show how some current movement has a Torah source but after it falls we need not refer to it any more.
As for Chassidut, it started as a populist rebellion against the learned elites and therefore was very problematic. One leader said horrible things about talmidei chachamim and another announced during Yom Kippur that he had seen through ruach hakodesh that the gates of Heaven were closed and there was no longer a reason to fast. He then had something to eat. The Baal HaTanya did a great deal to bring it back into the fold.Later the rebbes of Gur, the Sochochover and others made it a halachic movement.
As for reinterpretation of Halacha and hashkafa, what about the current notions about full-time life-long learning for all men, women supporting families while their husbands wave their fat fingers and rabbanim having the answers to all questions, including purely secular matters (even though it is, of course, absolutely forbidden to study secular subjects).