In recent years, there was a courtcase regarding the Rebbe’s Seforim. Among those called to testify was the Rebbe’s secretary Rabbi Leibel Groner, who was charged by the Rebbe with working to publish the Torah of our Rabbeim, and doing so for many years. In that capacity, Rabbi Groner merited numerous instructions and much guidance from the Rebbe about publishing those works.
During Rabbi Groner’s testimony, he was asked whether using the title “Melech Hamoshiach” was ever authorized, or allowed, by the Rebbe to be used in the Rebbe’s Seforim. This after noting that some Seforim bear that title, such as the Lekutei Sichos and “Bsuras Hageulah”.
Rabbi Groner responded that he once entered the Rebbe’s room and expressly asked whether they may use the title, and the Rebbe consented. Afterwards, he read for the Rebbe the exact wording of the title page of “Besuras Hageulah” which states Melech Hamoshiach after the Rebbe’s name, and asked whether that may be printed, and the Rebbe nodded his holy head in the affirmative.
Subsequently, Rabbi Groner related that once the Rebbe asked him why Chasidim are saying that the Rebbe is Moshiach, to which he replied it’s because all the criterion of Moshiach enumerated in the Rambam match the Rebbe’s profile, and the Rebbe accepted that.