It is important to remember that Chomsky has repeatedly supported actual genocides so long as the person committing the genocides was anti western in some way.
Dude. This is just not true. He didn't deny genocide. There are many reasons not to like Chomsky. I don't like him as of late. But, genocide-denial isn't one of them.
https://en.m.wikipedia.org/wiki/Cambodian_genocide_denial