”I have 1 simple question for Lubavitch Chassidim. If Moshiach comes today but he isn’t the Rebbe, would you accept him?’
Well, its a nuanced answer, and likely depends. If its another chabadnik, perhaps yes. If its someone who looks strangely Litvish, adds “V’yatzmach purkanei” to kaddish and asks for some more sugar with his fish, perhaps not