Yes. If they all go at the same speed (linear, in km/s) that means they all have different angular velocities, i.e. stars near the centre will have shorter pe

Yes. If they all go at the same speed (linear, in km/s) that means they all have different angular velocities, i.e. stars near the centre will have shorter period. That's why the article specified the period as about 240Myr at the position of the Sun.