Sometime in the few year lull of this thread, I asked my 90 year great uncle, the dayan of one of the biggest Chassidus in the world if this was true, and he told me it's "shtissim".
One story of 1 Rebbe who said that him and his friends thought their praticular Rebbe was Moshiach, is not a proof to be able to make such a broad statement. Nor are a few random quotes in a few random sefarim
And there definitely was never a Chassidus that was so public about their Rebbe being Moshiach.
And why weren't the Chassidim of the Baal HaTanya singing "Yechi"?
This is the only subject where I hear you making claims that aren't solid. It's so un"Dan"like.