Weather notwithstanding, I say Rupp can break the AR just from the very fact that he is coached by Salazar and he is entered in the race. Why else would he be entered in the race if he couldn't give the AR a serious run?
We know that Salazar only enters Rupp in races for a purpose.
If this race was about sitting and kicking, Rupp wouldn't be in it because we know he hasn't been doing much speed training.
Maybe he is just in the race for the sake of experiencing competition. That could be the case but I doubt it. Its an off year and he can do that later in the season after his kids are born.
All signs point to Rupp entering this race because he is in very good shape and wants to take advantage of it to do something special before he takes time off for the birth of his kids. Moreover he is going out of his way to travel all the way to Oslo. A meet virtually synonomous with very fast races.
Nothing else makes sense to me about him entering this race except that he is going for the AR and Salazar believes he is in shape to get the AR. Therefore, I say he gets the AR. Again, weather notwithstanding.