Is NE culture dying/diluting? If yes, what are the reasons? I am specifically interested in the answers from Arunachal, Tripura and Nagaland. What can be done to prevent such changes?

Is NE culture dying/diluting? If yes, what are the reasons? I am specifically interested in the answers from Arunachal, Tripura and Nagaland. What can be done to prevent such changes?