If the freeness encompassed saying "let's have a civil war", "these people are your enemy", "buy weapons for the incoming civil war", and selling t-shirts with a proposed civil war start date, then maybe?

How do you think civil wars start? And how many actual wars have been started by lies? Usually by the instigating government or yellow press, but in this case it's DIY yellow press letting people make up their own lies.

Incitement isn't permitted by any interpretation of the 1st amendment.

The current state of affairs offers nothing more granular than shutting down all of Parler in response to their failure to moderate this speech effectively.

Discussion? I haven't seen discussion come out of the US on a number of topics for decades. Discussions might start, but someone comes along and starts incoherently screaming.

Lies are often how wars start.

I suspect you believe that as an article of faith, but it makes me think you haven't been on the internet in decades. Go onto thedonald dot win and you'll see hundreds of thousands of people who have created an insulated bubble where assertions that support their preferred outcomes are articles of gospel.

If you can go on there and convince a single person that the election was legitimate, that ballot security measures make it impossible for their beliefs to be true, and that Biden was legitimately elected, it's possible for the proposition "free and open discussion can diffuse false ideas" to be valid, but if you can't, then you might want to reevaluate.