Zhang Yi's wives treated Wu Xinyue well because they knew that indirectly because of Zhang Yi she ended up dying in the past before Zhang Yi went back in time after they were married Wu Xinyue took a celestial oath and finally knew the whole truth.
Wu Xinyue was a little shocked to learn that she and her mother had died and like her mother, she was angrier at Feng Ran in this situation than at Zhang Yi who didn't even know about the situation.
But in this life, Feng Ran and she were more friends and that is why Zhang Yi's master escaped being beaten again, after learning about it Wu Xinyue was better off knowing part of the secret of why Zhang Yi was so strong.
Of course, his talent was the biggest reason, but surely going back in time twice helped him to become much stronger, so she got closer to Zhang Yi because he knew they should be together a long time ago.