Greg Yong confirmed in a podcast that the cars will not be electric. Although planned to be originally, he mentioned after riding an *unnamed* ride in Singapore, they didn't like the experience and preferred petrol engines to the new electric tech he observed in Singapore. He also said that the cars currently running around on track are not the finished product (though the disability accessible vehicles will be electric). All the petrol engines have been rebuilt.
Additionally, he confirmed that EarthStory (the infamous AI folk) were told what the concept was to be, and the coaster was purchased already. So fair to say that the theme was not borne out of the AI concepts - it was just visualising what they'd been briefed.
He was asked about Motocoaster. He confirmed they're not ready to do (or talk) about anything yet, but that it is on their minds. He did say it makes sense to integrate it into Rivertown, "in time", but ensuring the park has a sustainable future is a priority, so not yet.