1. It enhances the experience of Rasa within the reader/viewer.
2. It does not subvert the original narrative.
Modifications done in order to promote ideologies are the worst.
Here, initially the King refuses to recognize them both. But a voice from the sky spoke to the gathering...
Now, if we look at Kalidasa's "Abhijñānaśākuntalam" we find a few innovations ...
1. Before taking leave of Shakuntala after their marriage, Dushyanta gives her his ring, and tells her to show it to his countrymen as a proof of her being wedded to him, when he sends for her.
4. Dushyanta, fails to recognize her She is unable to show the ring.
5. A few days later some fishermen find the ring in the stomach of the fish, and gives it to Dushyanta. He then recollects his lovely wife. A changed man, he repents. Strengthening his resolve, he helps Indra in a battle against the Asuras.
The kid is Sarvadamana, and its mother is none other than Shakuntala.