If I were you, I would choose to 'Copy' save files to the thumb drive. When I upgraded my HDD, I chose 'Back Up' to the thumb drive. All of the movies and TV episodes I had would not play- I got a message saying that the copyright data had expired.
I lost like 10 movies and maybe 50 TV episodes; couldn't watch them. --- '03 Mustang GT- Flowmaster exhaust, Maximum Motorsports subframe connectors, strut tower brace, k-member brace... PSN: officersweetpant