This is all from this year's EuroBike show, so 2018-2019 models probably won't be available until later in the year, particularly here in the US where most European bikes are slower to arrive.
Have you checked out Riese & Muller's website for the 4 versions of the Load that are in production now? Hopefully, some other info will pop up soon from Eurobike about this new product.
Brett Thurber from The New Wheel in San Francisco, CA interviewed Heiko Muller from Riese and Muller about the new Load 75 bike at the 2018 Eurobike Show in Friedrichshafen, Germany:
YouTube Video Interview posted on July 30, 2018 with Heiko Muller and Brett Thurberon the topic of the Load 75 electric cargo bike.