exactly. the poster you are responding to is pretending that the boundaries of polite conversation have always been the same as the boundaries of legal speech when that's obviously not the case and has never been.

According to the Twitter files, Silicon Valley enforces it at the behest of the federal government.

Not clear why you're getting downvoted, but this is the exact right answer. The Twitter files was proof that the Federal government put pressure on Twitter to censor specific viewpoints.

What was the pressure?

There was often no (but sometimes) pressure, Twitter was aligned enough with most of the requests it seemed.

Regardless, does that remove the offense?

The offense being requests to remove revenge porn?

Somehow, I don't think that the material covered by the so-called "Twitter files", or the material not covered by them (e.g. Trump asking directly for deletion), is what the GP was referring to.

I could be wrong, but I doubt it.