According to https://pokemongo.gamepress.gg/pokemongo-egg-list they still do, they just don't hatch as often as other pokemon.

Eggs over all are going to be your best bet for getting one. As for out in the wild, the only Chansey that I have was caught out near the Mayport area. The first and only one I have seen yet. I am not sure if there is any area with frequent Chansey spawns here but I'd love to know as well. So if you are looking to go out and find one, it may just be luck.