Mashiach cannot be min hameitim because of the following simple reason.
1] habad is never wrong & whenever there is a source contradicting what they say , there is a way out. There HAS to be one.
2] habad with all its mashpi’im , rabanim, thinkers, ovdim, maskilim, rashei yeshiva, mothers , temimim,mekuravim, mekarvim , shluhim, adherents and hasidim ALL OF THEM , without fail, were saying pre 3 tamuz that their rebbi cannot die because there is a nevua that their rebbi is mashiach.
3] nevua letovah cant be batel.
So how could habad entertain the thought that mashiach comes from the meitim?