It's a completely different vehicle. The door design is dictated by door aperture design which is dictated the body design which is central to the whole car's rigidity, how the suspension is mounted and stressed etc. Everything has cause and effect. In typical Porsche thoroughness the first generation model was built like a tank so as it could withstand the rigours of off-road use without the body going out of shape, doors sticking etc etc. Porsche didn't want their first SUV to get a reputation of being flimsy. After all it was a monocoque (no separate chassis) so the body strength was critical. And while Porsche claim the second-generation body is 'stiffer' there's a big difference in one-off stiffness test against a twisting force and a body withstanding repeated torsional loads as happens in an off-road environment.
Once Porsche (and Mercedes Benz with its first-generation M-Class that was built on a separate chassis) realised that their customers didn't want to take these luxury 4WDs off road the design brief on the second-generation changed altogether. Again, I'm not disputing that Porsche's engineers have done good work in deducing the weight but their task was simplified by the change in design direction.