They are just stats with avatars at this point. None of them have personality or any actual impact on the story bits that were included with this game. I'm fine with either way losing them or keeping them. It really makes no difference, even maintaining the stats would be a waste unless the sequel is just a new coat of paint. If the sequel is drastically different PvE and PvP wise then a clean slate may be the better option. Personally I don't care and don't waste your time telling me to "delete your characters then" like you told someone else who disagreed below. I'm sure people will all decide for themselves when the sequel is released.