World Rallycross promoter IMG is in talks with the FIA and manufacturers to flesh out the vision. Together they're discussing the EV racing format, the cars themselves, and how the event will fit into the larger race weekend. Peugeot, Volkswagen, and Audi, who all support current World RX teams, have previously expressed interest in bringing EVs to the series.
World Rallycross Managing Director Paul Bellamy told Motorsport that the concept comes from the wishes of the manufacturers. He says the short races suit EVs well. Bellamy also says electrics are a good fit for the series because "the cars being used relate to the cars that you see every day on the road."
That last quote is telling of the larger EV story. As battery-powered cars become more mainstream, not only will we see them more in our day-to-day driving, but they're also beginning to become integral to the larger automotive landscape, which includes the world of motorsports. Just look at all the manufacturers jumping to Formula E as evidence of that.