This is from Sichos In English; Many people use the event of chassidim singing Chaeiley Adonenu Moshiach Zidkeinu to prove that the Rebbe did not want us to identify him as the Moshiach. This beautiful analysis shows that quite the opposite is rally true.
What is the Rebbe's position on identifying him as Moshiach?
Rabbi Even Yisroel on p. 197-98 cites a farbrengen from 1991 when the chassidim sang a song identifying the Rebbe as Moshiach, to support his assertion that the Rebbe 'tried to quash all speculation' about his 'Messianic role.' The author writes that the Rebbe “stopped them quickly and said 'I cannot leave here now, but after hearing such a claim I should leave this room as a protest.'” (It should be noted that the word ‘protest’ as translated by the author does not appear in the original Yiddish and is an error.) The author neglected to mention that at a 1984 farbrengen when a similar song was song, the Rebbe said that the focus on the identify of Moshiach detracts from the work of bringing Moshiach. To understand the error of Rabbi Even Yisroel, it is necessary to explore these 2 farbrengens. The 1991 sicha was completely different than the one in 1984. In 1984, the Rebbe was screaming that the publicizing of the Rebbe as Moshiach goes against and stands in the way of spreading Chassidus and pushes people away. He spoke with a lot of pain and harshness. Conversely, in the sicha of 1991, the Rebbe did not utter one word in that vein. In fact, the Rebbe was smiling and spoke just a few words in a quiet voice when he said 'you sing this song with these words while I sit here by the table. . . I should have walked out. But I won't. . ' There are 2 reasons which were given by the Rebbe which were left out of the book. The first reason is that 'it is not going to help anyway. The Chassidim are going to continue saying what they are saying.' The Rebbe smiled when he said that. Unlike in 1984, there was no anger or talk about destruction. And the second reason the Rebbe gives is 'I don't want to disturb the sheves achim gam yachad.' It is a farbrengen, there is unity among chassidim. He didn't want to do anything that is going to disturb that unity. The book did not point out that he most certainly did not say it is wrong, terrible, or destructive to identify the Rebbe as Moshiach. There was not one word of that nature. All he said is he should have walked out. Because if he is remaining to sit at a public farbrengen while a song identifies him as Moshiach, he is publicly admitting he agrees with its content. At that time, the Rebbe did not publicly acknowledge this. In other words, it wasn't the time yet for the Rebbe to be publicly acknowledge this.