I've never heard of this and don't know what HW3 is, yet I will still speculate that the plan is "If that turns out to be the case, we will upgrade those who b

I've never heard of this and don't know what HW3 is, yet I will still speculate that the plan is "If that turns out to be the case, we will upgrade those who bought HW3 FSD for free. And we have designed the system to be upgradable." which is what it says in the link you provided.