Maybe there are other reasons they are pursuing this just now.
It is easier and cheaper to make Al frames circular, however now we are into Resin and fibre the frames will be made in molds, will cost about the same for either shape.
Building in fibre, internal bulkheads can be molded into the frames to support the pressure inside across the flat area (while a circular fuselage does it naturally.)
Could be used to improve ground clearance or stance ( like flattened engine cowlings?)
May have areodynamic ramifications too, particularly in nose high attitudes?