> don't use too much cash, lest you run afoul of banking regulations or become a victim of civil asset forfeiture

Don’t hold too much cash. That single-handedly neuters the latter. Unless you’re spending $10 to 100k a month, banking regulations won’t give you an issue. (Below, you’re innocuous. Above, you’re big enough to find a bank that gives a fuck.)

Notice they don’t mention anonymity, just “privacy”. I’m kind of tempted to read it as privacy from third parties but not privacy from the government.

That's not a direct quote from an FBI spokesperson and instead just part of the subtitle of this article. I personally wouldn't read that it's "private, and not necessarily anonymous" as it seems likely that the author didn't distinguish so strongly between these things.

To the point of anonymous cash transactions, I strongly suspect there are ways to acquire cash in a way that the bills which are used in a given transaction aren't necessarily traceable to the individual who made the transaction. I've heard mention of such tactics but never tried to put them into practice because I don't care enough (in most cases) to make it more than theory.