If it was about the speedway engine, which it isn't, there's absolutely no reason to go electric, just like in other motorsports, the carbon footprint of the actual race itself is barely worth registering in the grand scheme of things, the only reason other motorsports have gone/ are going electric is to attract the motor industry money... which speedway has never had to worry about.
We are never going to live in a world without oil, we just need to source alternatives for the mass users to enable the rest of the planet to use oil where practicable