Depends on what you mean by pre-industrial. I think that what you say is true for most of recorded history, but perhaps not for the paleolithic era. That was probably peak human freedom, at least in my opinion
A bit much no?
The paleolithic era was when you'd get killed by some beast while walking through a field, killed by an arrow from some tribe nearby, or die by the age of 30 from the simple common cold.
By "free" you mean less responsibility? You didn't have to work and worry about a roof over your head?
Your understanding of freedom is also problematic. Hunter-gatherers had enormous self-responsibility if the wanted to stay alive. They had to work HARD just to survive. Freedom in wilderness circumstances does not mean what it has come to mean in modern society. It implied enormous responsibility. Nowadays, modern man has lost all conception of freedom beyond days off from work so as to fritter away his time in hedonistic pursuits.
Steven Pinker goes into a lot more detail in his recent book Enlightenment Now.
Even if Ted's mad dream was somehow achieved through mail-bombing (talk about insanity - at least Charles Manson's plan had the remote potential to start a race war if the frame up kept on succeeding and a cycle of violence was kicked off.) we'd be right back to where we started in rebuilding technology from scratch or worse yet scavenging it to survive better.
Anyone in an actual survival situation knows that such concepts are claptrap as they'd take any unsporting advantage to survive and use up irreplaceable resources to do so. Because your life is not a sport. If you need to make multiple life or death decisions as part of your lifestyle you are clearly doing something very wrong.