As mention the issue with getting wet is that they don't dry well naturally, even kits when born have their mom to lick them dry. Like rabbits they can also go into shock if dunked in water, but I think rabbits are more prone to that.
A water bowl has many downsides, you would need to change it multiple times a day to keep it clean (poop, hay, and dust all end up in it), you run the risk of the chin jumping in it or dump it (requiring drying), and it's more likely for a chin to accidentally inhale water when drinking since when drinking their nose is right at water level (it happened to someone I know and the chin died). The only real upside to a bowl is that you know the chin has access to water where as a bottle can sometimes not work so you have to check to make sure water is coming out. With a bottle the water stays clean, chins in the wild drink water droplets, like dew, not from pools or streams of water (which don't exist where they live) so licking drops of water from the end of a bottle tube is likely more natural. I've had chins for almost 30 years and never had a problem of the chin not getting enough water from a bottle. On average chins only drink about 1-3 ounces a day, so they really don't even drink a lot.