Destiny 2 will be leaving Blizzard's BattleNet platform and transferring over to Steam in October. This move will also be marked with a transition towards a free-to-play model with optional expansion packs, as well as a whole bunch of other general changes.
So if you would like to have your PC character survive the move towards Steam, you'll need to link your two accounts over at Bungie's PCmove website. The service will become available on August 20th and will allow you transfer absolutely everything, including your expansion purchases, so do make sure to go through the process or you'll find yourself starting from the very beginning on Steam.
Similarly, if you're planning on playing Destiny 2 on multiple platforms, you'll want to sign up for the Cross Save features over at the official website. It will become available on August 21st and give you the ability to progress the same account regardless of the platform you're playing on. However, you will only be able to designate one account as your "main" one, so do make sure to choose your most active one if you're already playing on multiple platforms.
You can read a little bit more about these features, as well as check out what's happening with Destiny 2 as a whole, over at the recently posted developer update.
