Yeah that's what it looks like, even though if someone had bought the same car without FSD and I bought it from them privately, I would have NoA
Tesla has control over their vehicles (new, inventory, pre-owned) - such as the whole Free Supercharging (which was no longer supposed to exist, but, was brought back)... Then, on the vehicles that were supposed to have Free Supercharging for life, they removed them (Tesla Pre Owned vehicles)...
You can only go by what the vehicle has listed... If it has AP, you get the two features assistance features listed in that chart, and can add FSD for the rest at the higher price ($6k).
If it has EAP (which was discontinued), you can now add FSD for the $3k price, instead of $6k.
If you have nothing activated, only AP + FSD is available now.
You can not get a refund of any purchased features, so, no possibility to downgrade (at least post-delivery, from the wording on the website).
Tesla can take any of their inventory vehicles and change their software licensed/activated options on them before they sell them. They discontinued EAP, yet, still have inventory cars with EAP (they could have easily marked them as AP, or FSD - but with EAP listed, it gives them a potential for selling FSD to the customer). I purchased my X a couple of weeks ago (new inventory) with EAP - will probably not upgrade to FSD as I will be paying for nothing other than a possibility of future features and future hardware upgrade.
A private party sale is subject to whatever that owner had (or didn't have).. If they had AP, then, $6k FSD is your only route. If they had EAP, then $3k is your FSD option. If they had nothing, then, $3k AP + $6k FSD is your way.