Yes, the spec sheet indicates 1500V isolation from input to output. Note that 7805 and similar regulators have good rejection of mains-related ripple (50 to 120 Hz), but may be insufficient to reject the higher-frequency ripple of the switching module: you may need to add passive filtration between the switcher output and the regulator input at each device.
At 580 kHz switching, the ripple will be in the MHz neighborhood; the data sheet specifies 100 mV pk-pk in a 20 MHz bandwidth, with an external 47 uF capacitor.