Indeed there is a Hybrid and Plug in version but as you say, not currently on the scheme and the 3 that are, are EV’s.
It could mean the hybrid, PHEV or indeed both could be coming to the scheme soon. It could also mean Kia hadn’t got a spare EV availbe at the time, to bring to the event and supplemented it with a Hybrid of some form, as they look near identical inside and out!