Is Hindi replacing our tribal languages?

Ever since I put my child in school, he has started speaking in only Hindi, because his teachers teach him in Hindi, as he told me when I asked him how he could’ve forgotten his mother tongue. Hindi seems to have taken over almost all the Arunachalis who spoke their various native languages.
Almost everyone in Arunachal Pradesh speaks Hindi. I have heard that even elderly female vendors like to talk to their customers in Hindi. Every youth of Arunachal is heard imitating the pure Hindi pronunciation of mainland Hindi speakers and deliberately avoiding their native dialogues and feel shy to talk in their dialogues. Therefore, proper speakers of their dialects are rarely found in Arunachal.
Arunachal itself has adopted its name in Hindi and we feel proud to speak Hindi because we are true citizens of India. Our ancestors were taught Hindi by the mainland Indian Army during the war against China, as my father narrated to me in my childhood. Hindi language has become a better medium to communicate with mainland and other languages speakers of Arunachal because we are living with different people and diversity. For example, I cannot speak and understand Monpa, Tangsa, Memba, Assamese, Bengali, etc. But it is clearly seen that our own tongues are in danger and are on the verge of extinction.
If we do not care about preserving our native tongues and replacing them with Hindi and English, our ancestors must be reborn. Our next generation will be able to understand the meaning of the spoken dialogues only from the dictionary of the tribal languages. So now is the time to teach our children to speak and interact in our dialogues from a very early age. And there should be teaching of tribal language in every school in Arunachal. It will hold the light of preservation of our own tribal languages in the days to come.
Majum Ketha,