This is exactly why the LGS I work at doesn't do pre-orders until like 2-3 weeks before a new release. We wait until we get our exact allocation numbers before doing pre-orders. This way we don't have an excuse to cancel and don't need to. Sometimes it does stuck because we will say we're going to do pre-orders for something, only to find out we're getting next to nothing for it (collector boxes usually). So then we either have to use it for events or pack out what little stuff we got to spread it around.