Yes, with the exception of SAB (which does not operate unguarded) and the quiet pool at BCV is unguarded, but they turn the lights out at a certain time and you are not supposed to swim in the pool after hours.
Just returned from BLT and the guards close and cover the pools but the pool stays open all night. The same with SSR and AKL. Most theme pools will remain open unguarded and cover the slides. If you are not allowed to use them after a certain time, the pool area will be dark or posted as closed.