The genetic link between India and Australia is not conclusive. Most recent Genetics paper on the earlier mentioned links has found no recent links.
Also Dravidian and Veddoid are 2 different races. Some Veddoid have taken up Dravidian languages just as other Veddoid have taken up Indo-Aryan.
In Sri Lanka is the only distinct Vedda population and they speak a creole that is neither Dravidian nor Indo-Aryan; it shares more with Indo-Aryan but has a substratum that is distinct and different from Dravidian and Indo-Aryan. India does not have distinct Vedda populations as they have linguistically and culturally assimilated into the surrounding Dravidian,Indo-Aryan and Munda speaking populations.
I would certainly agree that a recent India-Australia link is not proven.
My argument was that those people we call Aborigines are new people. Supposedly they supplanted most of the original people. They are said to have come from India and Thailand 12-17,000 YBP. Any genetic relation that far back will not show up in genes.
Furthermore, Veddoids and other primitive types in India (yes, there are some in India, not just Sri Lanka) have skulls that plot Australoid next to Papuans, Melanesians and Aborigines. If there is no connection, why do they have the same skulls? Tamils also have Australoid skulls showing the same connections.
There is a very ancient and primitive group in Nepal called the Nahali. The language was long thought to be an isolate and was recently thought to be extinct. However some speakers were found not long ago. More recent though highly controversial studies suggest that Nahali is an Indo-Pacific language related to the languages of New Guinea. I believe this connection is correct. If there is no connection between India and Australia, why the language connection?
Also, the Andaman Islanders are Australoids by skulls. So once again we have an Australian connection with the most primitive people of India by skulls. Some theories suggest that the Andaman languages, long considered isolates, are related to Indo-Pacific languages. Joseph Greenberg thought so. I am not sure how well that is backed up, but if it is true, once again, we see a connection between India and Australia.