I really hope that this is account based and not character based. Having to unlock difficulties to progress a different class to level 30 as an experienced player would be a completely unnecessary gimp.
It would definitely sour things for wave of experienced players wanting to level their new arbites
Edit: although maybe these 2 things aren’t tied to one another. But based on how they let the weapon mastery system be effectively skipped with the sacrifice feature, I’d say chances are damn good that they won’t force everyone to play Sedition.