I don't know if our guardians character data can be transferred from current gen to next gen systems, this is something a lot of people are waiting to hear back from Bungie on. Also the norm for beta testing is that all characters and progression will be wiped at the end of each beta testing phase, it's so that everyone will start on a even playing field when the game goes live, but the people who have been in the beta will know their way around an lvl faster.