Aircraft design is very intricate. Change the CG, break the whole system.

Fuel is often placed in wings because adding/burning fuel from your center of lift means your CG doesn't significantly change through a flight and you spend less on pumping fuel within the aircraft. With batteries, you are looking at a constant mass from the beginning of the flight to the end... so you can place it anywhere. Electric motors are orders of magnitude lighter than jet engines. Also, you don't need to pump electrons against gravity so placing all of that weight lower has handling/performance advantages.

By using an airframe shape that is well known, they are reducing risk and appealing to existing pilots. By building it from the ground-up, they are taking advantage of differences between the tech.

eg: all of that weight in the fuselage instead of the wings means that rolling is going to be much more nimble. Yaw might be affected as well, depending on the placement/moment of the batteries.