I can't argue that your worries won't come true, but I can say that Starwood hotels have tended to have the "cancel the day before" policies for years, and I've not had any of them really cause me problems either.

But in all fairness, I may not be the most experienced in dealing with hotels and airline changes/cancellations. I will admit that even with all my travelling, I really haven't had that many times where I had to call a hotel and cancel a reservation. While it has happened, I guess I've been fairly lucky over the years.