I'm thinking this will just go hybrid as its only green option. If Toyota is like all the other car makers then creating a model that starts life as a fully electric model, then that discounts the TJ. They already proved that with the miraiAfter you're done with the I-Pace, it'd be an off-road friendly electric vehicle. Bigger tires, more lift!
We're more likely to see a hybrid than a full electric if the TJ Cruiser ever comes out. Not a bad idea actually since Toyota seems big on hybrids.