Today I sent a magic packet to wake my desktop computers – the one which should not have started – Asrock EXtreme-4 running Windows 10 1809 actually woke up? Retested by shutting it down and sending a wake-up magic packet from my phone and watched it start through the boot cycle, into Windows 10.
Follow up – I have confirmed – same method as above – my other 2 desktop computers (GA-MA-790GP and GA-P35DS3L) running Windows 10 1809 have been woken via magic packet from shutdown – not sleep, or hibernation.