Title is a bit disingenuous, the ruling actually says they are prohibited
from even talking to social media companies with “the purpose of urging, encouraging, pressuring, or inducing in any manner the removal, deletion, suppression, or reduction of content containing protected free speech.”
Government should not be cohering social media companies to silence speech, this seems fine to me.
ISIS probably isn't the best example, because promoting terrorism and advocating violence isn't protected free speech. Regardless, I don't think this would apply to a politician making a general statement like this, but government agencies working behind closed doors to suppress legal content.
It actually is protected free speech in the USA to promote violence. It is not protected free speech to promote or incite violence with the imminent threat of harm.
The American Nazi Party and the KKK won their SCOTUS fight over that, thanks in part to the ACLU.
"Free speech" is doing a lot of work there. As always.
For example, I think deliberate misinformation should be treated the same as harassment, fraud, and incitement. That is, a kind of speech that is not protected free speech. Just like defamation, you should have to reach an actual malice standard. But unlike defamation, there is not a clear "victim" to act as the plaintiff, so the state would need to step in on behalf of the people to act as one.