I appreciate the correction. You are partly correct; Chomsky did not in fact celebrate the sacrifices, but rather urged people to doubt their reality, in 1977, at which point doubting them was perhaps more reasonable than it is today: https://en.wikipedia.org/wiki/Cambodian_genocide_denial#Chom... https://chomsky.info/19770625/

That article was written before the worst of the killings happened in 1978, though it still seems outrageous to me that it blames the bad conditions in Cambodia on US bombings killing water buffalo; Chomsky touts "the destructive American impact on Cambodia and the success of the Cambodian revolutionaries in overcoming it" and describes reports that “virtually everybody saw the consequences of [summary executions] in the form of the corpses of men, women and children rapidly bloating and rotting in the hot sun,” as "fallacious", saying that they "collapse[] under the barest scrutiny".

The US bombings were indeed terrible, but (as the page you link explains) they did not kill anywhere close to the 600k people you claim, and they happened earlier than the Khmer Rouge killing fields, not at the same time.

I have corrected my comment to instead make the more defensible, though still perhaps controvertible, claim that Pol Pot celebrated the sacrifices in that way.