It would be in the best interest of the US govt. to protect the value of its bitcoin reserves. One way the US govt. could do this is to be the first to "hack" Satoshi's original stash,
not to seize it or steal it but in order to move it safely to the new quantum resistant bitcoin wallet(s) that would exist in the future.
Removing access to someone's coins because it has passed X amount of time makes no sense.
That change will most probably never pass the checks of the Bitcoin devs.
There are also reasons to never have access to those coins, like the Bitcoin Eater addresses:
https://bitcointalk.org/index.php?topic=1577203.0This definitely don't make any sense, as I think that's not even possible in the first place but if dev will introduce such protocol to secure BTC from quantum power, then I don't think anything can be done to secure Satoshi's BTC, as OP has raised a good concern, but I liked the answer of Headingnorth as if some good actor like USA or any other country.
With quantum power they will move Satoshies funds to a secure place but those funds will no longer be in possession of Satoshi. I really don't get this here like if that's even possible? I think I have to do some research here on why this can't be possible as some answers here are very short.
BTW thanks for sharing this thread link it's new to me.