What don’t you understand? Those websites that defame a company are liable for that defamation. In this case Google defamed a company in its AI summary and is this liable for that defamation.

> is there a truth requirement anywhere?

Yes, and it's called defamation when you don't follow it.

There is absolutely a truth requirement.

This is why you have to say "I think this person is a murderer" and not "This person is a murderer."

One is opinion. One is fact.

This isn't super hard.

And those tons of websites are liable for their misinformation. It's probably not worth suing some random blog because the author probably doesn't have money or lives in Russia. But Google has lots of money and a legal presence in almost every jurisdiction.