As of the present time and judging from previous games by Larian and their style, the most likely answer is no... in fact, you will be made to feel like you're being punished for not playing an origin character, and that you are missing out on things; that your character is a cardboard cut-out tied to a mop that does nothing and adds nothing whatsoever to the game.
Those of us here who aren't totally jaded are still hoping for some sign of genuine evidence that this won't be the case; Larian have said they want to make the custom PC feel more alive and purposeful... but they've also intimated that they've done things to make them so in the current state, and they clearly have not.
