The USB2.0 device is only an interface to your assets on the blockchain so if that technology becomes obsolete, I suspect the replacement will offer access in the new way. Same way movies are still accessible even though laser disc technology fizzled out.
Discussion
Sure, but getting a laser disk converted to play on any modern system is mighty difficult for the average user I would imagine. I know cold wallets are the #BTC standard, but I imagine a scenario where those devices either get corrupted or are no longer compatible.