Hello, that’s a very interesting question. I can’t say i really know, but what you propose does make sense. Perhaps the way that gravity affects air (colder air is heavier and thus goes down while warmer air travels upwards) has something to do with the way water freezes on the Earth, in terms of heat transfer. So yes, maybe in space the lack of gravity makes water freeze in a more uniform way. Similar to how flames burn in space as compared to the Earth.