Not necessarily. We are talking about wet spots in a lawn, not vast floodplain wetland complexes. It depends on the situation. In many cases, just discontinuing mowing will allow a wetland to ‘restore’, especially if you also yank up any invasive plants that appear. Planting a few wetland plants native to the area may be necessary depending on the seed source. If the site has heavy hydrologic disturbance like ditches or french drains, that does get a bit more complicated, but if you are already lookign at a wet spot, messing with that stuff is not needed. Conversely, creating a pond requires making a big hole, making sure it continues to hold water, and if you want to keep it a pond usually dredging it. Keeping the ecology and water quality of artificial ponds also appears to be pretty hard. And you have to deal with mosquitoes in a pond which you don’t if a restored wetland doesn’t have standing water. of course, a tiny pond or pool is going to be easier.
On older article with some interesting insights about ponds in winter:
Big freeze and ice is 'good for pond life’
I’ve seen several articles that discourage breaking the ice because of the shock waves it creates - suggesting that this can stress or injure animals. Have not seen any research to support or refute these claims.
I don’t break the ice on my pond. Mostly because it’s cold outside and I’m lazy. Doesn’t seem to be a problem as I still see tadpoles under the ice and all the melting and refreezing thanks to our crazy weather renews enough oxygen.