Or, if one believes the Rebbe is alive בגופו ממ"ש, one must question why he is saying silent. An unbelievable dereliction of.duty.
I know you're being sarcastic, but please don't decide what a Rebbe's duty is or isn't and certainly what would be a "dereliction of duty" for a Rebbe.
I'm reminded of a time when the "Tzfatim" set up "dollars" and as luck would have it, one of the Rebbe's secretaries walked by right before the time it "would start". So one of the gang leaders setting it up said, "Go tell the Rebbe we are ready for dollars." The mazkir responded, "I don't know who you are referring to, becuase my Rebbe decides his own schedule."
(This is the time to point out that the Rebbe זצ"ל did appoint specific people as official spokespersons, and those who say there are none except the rebbe are explicitly ignoring their Rebbes own words.)
ממ"נ, if the Rebbe appointed a spokesman for himself, they would need to hear from the Rebbe what it is he wants them to say, which again would depend on them being able to hear the Rebbe's words begashmius. And if the Rebbe appointed spokespeaple for specific orginizations within Chabad, they would be speaking now in that capacity, not on behalf of "Lubavitch".