It's kinda funny to see Chomsky make that point, considering he tolerates totally-not-genocides as long as the perpetrators are politically aligned with his views (or so he thinks).
To those who aren't aware, Noam Chomsky vehemently denied Pol Pot's mass murder of millions in Cambodia.
Vietnam invaded Cambodia and the US began arming Pol Pot and the Khmer Rouge in the late 1970s and 1980s, which again the Times covered, although slightly obliquely. Chomsky condemned the US arming Pol Pot and the Khmer Rouge.
Now you might say "surely he has come to his senses", except Chomsky went on to spread lies about the Sarin gas attacks in Syria.
There's probably more.
"Ponchaud’s book is serious and worth reading, as distinct from much of the commentary it has elicited. He gives a grisly account of what refugees have reported to him about the barbarity of their treatment at the hands of the Khmer Rouge."
So a book about the barbarity of treatment by the Khmer Rouge is "serious and worth reading". That is what Chomsky actually wrote back then if anyone is actually curious. Does not sound like what you claim he was saying.