They have two more launch windows on Sept 2 and Sept 5, and if they don't try it on those days the next chance wouldn't be until the end of September.
Basically, no big deal to scrub today, there was some question if they would even load fuel because of the weather forecast, but I think they need to launch at some point this week. The program hasn't really had anything go to plan or to schedule at this point.
Tough to know without being closer to it, but sometimes it feels like a crippling abundance of caution when 50 years ago they would have said just launch the damned thing.