For the longest time we believed the Earth to be the center of the universe. In 1543 Nicolaus Corpernicus proposed the heliocentric model which suggested the Earth revolved around the sun. It seems like common sense now but in the 1500s, this view was laughed at by many scientists.
If earth was 50% larger in diameter gravity would be so high that chemical rockets would'nt be able to break the earths pull and our intire space adventure vould be nothing but a Jules Verne story.
So if the folks at Kepler 425b are like us we're just a story and a dream for them, nothing they can come and see.
My point is, it's too far way for any of our instruments to measure the 'actual' habitable zone of that system. Too much guesswork going on.