Water freezes even if randomTickSpeed is 0. It'll convert to ice in any snowy biome when next to another block; it does not need to snow for this to happen, but does need to be the highest block in the world.
But I expected it to just stay water, not freeze, I thought, since dirt(to grass) is randomly ticked and effected by the gamerule, that water(to ice) who are kindof randomly ticked, that it'd be effected by the gamerule too
1. Lightning is completely unrelated here 2. This only effects water next to another block in snowy biomes, no need for it to snow That it's not mentioned, doesn't mean it's intended, I'll wait for a developer to reply
Water is not ticked by random ticks.