The Hebrew manuscripts of Matt 24:28 that the Greek was translated FROM say "gufah" - carcass / dead body, not a living one.  So I would agree with the conclusion.  At http://www.fivedoves.com/letters/aug2004/marilyna816.htm someone raised the question about the Greek meaning of the words "soma" vs "ptoma" and how Strongs seems to suggest that "ptoma" always means 'corpse' while 'soma' always means a living body.  Strong's has a lot of errors in it, and if what you see in it conflicts with another source, the other source may well be more reliable.
 
Matt 14:12 says "And the disciples of John drew near, and took up his body"
 
Since his head was cut off, its pretty safe to say that his body was dead at this point.  The Greek Byzantine versions of Matt 14:12 say "soma" while the Alexandrian Greek versions and Codex Bezae of Matt 14:12 say "ptoma".  Or in Mark 15:43, both the Alexandrian and Byzantine Greek versions say "soma", while the Western reading says "ptoma".  So a lot of the times, it depends on which Greek manuscripts you are looking at, but "soma" can definitely be used for a dead body.  "ptoma", on the other hand, does not even have to refer to a body of a man or animal, but refers to the state it is in (ruinous, etc).  However, the phonetic similarity between the two words seems to have made it easy for the implication that "ptoma" refers to a "soma" to be an easy one to make in Greek.
 
Now getting back to Matt 24:28, I think the very context here suggests the body is dead.  When did you ever see vultures gather around for a live body?  And this verse also has to fit the surrounding context as well.  Let's backtrack a few verses.
 
For there will arise lying Messiahs, and lying prophets, and they will give great signs and wonders, so that, if possible, even the chosen ones they will lead astray. (Matt 24:24)
 
Here we have a discussion about false prophets and miracles that might testify to their validity.
 
Lo, I beforehand have said to you, that if they shall say to you, 'Lo, he is in the desert', do not go forth, or 'Lo, he is in the inner chamber', do not believe;  for as the lightning lighteneth from the east, and is seen unto the west, so will be the coming of the Son of Man (Matt 24:25-27)
 
IF a prophet's miracles produce the fruit of unrighteoussness, he is obviously a false prophet.  Don't be led by the wonderoussness of the miracle - who the miracle testifies to or against is what helps us understand what power is behind it.
 
After telling us this, we get two lessons from nature...
(1) The behavior of lightning
(2) The behavior of eagles / vultures / birds of prey.

To me, it seems like the statement of Matt 24:28 fits well with the statements before it about false prophets and their miracles.  If they work miracles that produce spiritual death, we don't look for the the G-d of Life to be behind that.
 
Or perhaps this statement is more connected to the verses that come after it.  I'm not sure.  But there's got to be a complete flow of thought from 24:24 to 29 and on, and so far, I'm not sure I;ve heard an explanation that really connects all those dots to the point that I'm satisfied with it.
 
Shalom, Joe