The question of whether Rav Schneerson ZT”L ever declared himself to be Moshiach, is more a criticism on the Lubavitcher Rebbe himself as opposed to his followers.
He’s not Moshiach. He won’t be Moshiach. He never was Moshiach. Those are inarguable facts that every frum Yid should know. If you claim otherwise, you aren’t a frum Yid. If he claimed otherwise, then perhaps he isn’t the Gadol we thought he was. Baruch Hashem, even from this video I fail to see how he every claimed to be Moshiach.