Disagree strongly.
But am totally not interested in getting into this argument.
If you learn this Rambam like you learn all Rambams, you would never say that the Rebbe fits the description.
If you hold the Rebbe is Moshiach and want the Rambam to shtim with that belief, you can drey the Rambam like a pretzel and have it shtim.
I wish there would be intellectual honesty on both sides of this argument.
I believe that after learning the Rambam in depth without preconceptions - there are 2 conclusions:
1. It is very mashma that Moshiach can come from the dead, as long as he wasn't killed. (I might be the only Litvak alive who will concede that point )
2. Nobody since Bar Kochva came even close to being Bechezkas Moshiach. Probably nobody even fulfilled 1 of the tnaim!
(If your me'aiyn in the Rambam, you'll realize that the mekor for e/t he's saying was the story of Bar Kochva. So when you try to figure out what each tnay means exactly - think Bar Kochva)
I don't see how you can be so amendment that the Rambam CAN'T be talking about the Rebbe (not even 1 of the Tna'im? for real? There are at least 2 that are beyond debate: ואם יעמוד... מבית דויד הוגה בתורה ועוסק במצוות כדויד אביו, כפי תורה שבכתב ושבעל פה...).
I have a letter from my great-great-grandfather (A Chossid of the Rebbe Rasha"b, a very respected Rov, served at one point as the Rebbe Rashab's personal Rov), way before anyone accused Chabad of being overly messianic. He was writing to a friend of his, the Rov in Chernigov, both are people you wouldn't accuse of excess Chassidishe zeal and narrow-mindedness. In the letter he describes in great excitement a "discovery" he made that the Rambam in Hilchos Melachim matches the Rebbe Rashab perfectly.
If people said about the Rebbe Rashab that he fulfilled ויכוף כל ישראל לילך בה ולחזק בדקה, ויילחם מלחמות ה' how much more so for the Rebbe with his network of Shluchim and Chabad houses and numerous campaigns he led can fit the bill.
I understand that someone can think otherwise, but to accuse someone who understands it that way with intellectual dishonesty?