The thing is, nothing that usually changes things applies to Chomsky. What he did was most certainly not a normal thing to do in his time. Like one might say about George Washington or even further back, like Clovis. By today's standards they were morally wrong, but not by the standards of their time and they advanced morals. They made things better.

Chomsky is wrong by the standards of his time and is making things worse rather than better.

It was very much the opposite of Chomsky's ideology as well. So it additionally means he's fake. BOTH on his morals and politics/activism, from both sides (ie. both helping a paedophile, and helping/entertaining a billionnaire).

So it's (yet another) case of an important figure that supposedly stands for something, not just demonstrating he stands for nothing at all, but being a disgusting human being as well.