As for Fr. Ferrao's new thesis, I am not sure if it needs approbiation or needs to be seen as some have opined as an exercise in "historical revision". It could also be said an exercise in dialectical reasoning or didacticism. Rock carvings and idols of worships said to belong to pre-historic times can be accounted as belonging to cults. These cults and other groups may not have formed themselves into organized worships of particular deities. Hence, the formal concept of Hinduism hadn't taken place. Considering that there were temples and other structures that symbolished some sort of formal worship that now comes under the umbrella of Hinduism before the arrival of Portuguese does show that the religion had taken roots. The Portuguese era is less than 600 years in India. The destruction of temples and the ruins found later does tell a story of a religion other than Christianity having existed before the Portuguese arrived. Maybe Fr. Ferrao's breaking new ground or general summation, as I see it, needs insightful look by noted historians.
Eugene