It looks like Mercs next generation S-Class will be using a sole hybrid powertrain. According to Autocar it will have up to 62 miles of pure electric range, as well as a brand new 4Matic AWD system. It will be built upon a newer version of the ARA platform and may be available exclusively in LWB. https://www.carscoops.com/2019/01/2020-mercedes-s-class-hybrid-electric-eq-s-use-different-platform/