Sounds like the airline was just acting proactively by trying to make arrangements in case the weather didn't cooperate but they weren't prepared to cancel the flight. It makes sense, if you're not 100% sure that a flight will be canceled then you don't want to start moving people around and messing with people's schedules, but at the same time you probably don't want to start booking more people on that same flight. I'm not sure if this is what was happening, but that's what my guess would be.