Both calling something disinformation and disinformation itself are clearly protected free speech. Especially if the "disinformation" is political in nature.
How do we determine when something is true or disinformation? That's what good faith pro-social and pro-truth people ask. They talk process, principles, and reasons.
I mean, a lot of very smart people told me that you shouldn’t be allowed to say things like “masks don’t work”. They also said hate speech isn’t free speech. Who am I to argue?
Personally I found everything in the article to be ludicrous and to have Jack-all to do with the First Amendment, but I am not very smart.
Withholding federal funds from colleges for not cracking down hard enough on speech the government doesn’t like isn’t related to the first amendment? Or it is but it’s ludicrous?
The 1A is regularly used to decide cases about funding as speech; Rosenberger v. University of Virginia for example forbade U of V from withholding funds from religious news organizations on campus.
I am sure there are arguments that this behavior is within the bounds of the constitution but the 1A definitely applies.