It does, however, factor into how easy it is to reschedule reservations.
We have an April use year. We usually travel in October. If we have to cancel an October trip, as long as we cancel it more than 30 days out, we can use those points until March 31st. (30 days out the points go into holding and there are more restrictions). We'd probably switch the vacation to January. If we travel in Feburary, and need to cancel a trip, we only have until March 31st to make the trip.