The keys can move without the coins moving. Think of it like the ultimate Casascius coins. There's no way to know whether or not Satoshi cashed out. I can't find the thread, but I'm pretty sure Adam Back even said this on bitcointalk and said that that would be how he'd move the money if he were Satoshi.
I saw part of that video the other day and what you and the guy in the video are saying is absurd. This guy is all butthurt that Roblox can't monitor and ban people for what goes on in Discord chats. How and why would anyone expect Roblox to enforce it or even care what happens off of their platform?