We don't have exact proof though. Unless I see proof with my own eyes, then I can't believe that. It's easy for Microsoft representatives to use utter bragadocio and say it's more powerful when they do not work with Sony and know their rival's specs and techs. That's like me saying I have browner eyes than Tyaren without even knowing his eye color.(Which I believe is green..?)
EDIT: Just looked up the stuff, Microsoft seems very confident it'll be the most powerful console. Well, Ps4 Neo doesn't have an exact release date yet, but I expect they'll prolong it to have more time to surpass it. Remember, you can make a big card tower and call it a day, but that's futile if a rival is still building long after you finished.