Not very not time ago, the English dictionary, Webster or something like that, decided to add Internet to the dictionary. How long have we had internet? Internet was common used since 1994 probably, but it wasn't added to the dictionary until recently. I think what they take into consideration is whether this word will still be used in long term. And I believe the same method is being applied to this Chinese dictionary. Since we have been using this word, 雞, as a way of meaning hookers, I think it is reasonable to add that to the dictionary.
From this news, I can still see that some Chinese women are still not very open to this new age or new era.