The main difference between a departure ATIS and an arrival ATIS is the frequency it's transmitted on. Departure ATIS frequencies are reused at quite nearby airfields (Bournemouth Dep ATIS 121.95, Oxford Ground 121.95) and so, in the air, you may well get interference when you try to listen to a Departure ATIS. Arrival ATIS frequencies are used more sparingly. It's nonsense to say that you can't listen to a departure ATIS on arrival. It can save RT exchanges but you need to be aware of its limitations. Some ATC units, like Bournemouth, expect their home-based a/c to use the Dep ATIS on recovery but I have come across the odd ATC unit that get all pompous about it being a Departure ATIS.