I would ALWAYS call if for some reason, plans fell through. Sometimes you can't help unfortunate events. I would call. Conducting business myself, I know that a no show can be costly. Especially when you leave a girl waiting and turning calls down because you were supposed to meet.
At least be a man and call her. It's not like she is going to flip out on you and throw your stuff out on the lawn. You have no stuff at her place for her to throw. But a courtesy call probably wouldn't hurt to let her know you can't make it. At least that way she can plan the rest of her night.
Amazing how it works. The same guy who would stand the girl up, is the same guy who would post a shitty review on her if she did the same thing back to him. Fortunately, any SP I have set up with has had enough respect to call me if there was a problem and they couldn't make it. Maybe I'm just old school when it comes to mutual respect.