I heard more about Moshiach being a Misnaged from a Litvishe friend.
The way he told it was like this.
Moshiach will be a Misnaged. Why? Because he will come and say kaddish, and he will not say veyatzmach purkanei vikareiv meshichei (ויצמח פורקניה ויקרב משיחיה) as part of it (because if Moshiach has already arrived, it will be out of place, anachronistic, to say it). So that proves he is a Litvak, and not a Chassid.