Yep, Joshua can still win the fight because of his height/reach and longer experience in the heavyweight class. Usyk is a solid technical boxer with southpaw advantage since a southpaw boxer faces more orthodox boxers in his career. We can see how AJ looked confused in their first match. However, if AJ can mimic Fury's strategy, he can win it. He just need to put a lot of weight, and power. Don't go technical against Usyk, but go head on full YOLO. He is bigger than Usyk who was a cruiserweight boxer.
Extra weight was the reason AJ was slow against Andy Ruiz and lost via TKO. Heavy, powerful but slow AJ will be the easiest target for Usyks punches. During the fight AJ did not make series of punches often. Being heavy will make him throw 1-2 combinations maximum, because series will make his stamina go down quickly. We all know that Usyk likes to throw a lot of punches. Where one make 2-4 punches, Usyk throw 10 minimum. In their first fight Usyk connected almost 20% more punches. Heavy and slow AJ will be a perfect target.
If AJ gains weight for power, the fight will end with UD but with even more points advantage by Usyk. Maybe doing opposite will be the key. Maybe loosing weight and have it identical to Usyk will do the trick. Speed vs Speed.