The entire A&N islands are not about to become uninhabitable, the IN will simply use a few of the uninhabited islands for their training purposes, the rest of the islands will be completely untouched.
Anyway, the IN is going to be using these islands to test conventional weaponry, I don't see how this will lead to the extinction of any form of wildlife- the occasional missile hit is not going to do much damage to the ecology at all.
Dear friend, I dont know how much you know about Andaman and Nicobar.
Just sharing few facts with you
1. There are around 350+ islands out of which only 30-32 are habbited, out of then most people can at max visit 7-9 islands rest are occupied by tribals where common public is not allowed, and for rest the permission is not granted. This is because both govt and world has recognized that zone to have some of the worlds most diverse flora and fauna, marine life and tribes like Jarava's.
2. So far, about 2,200 varieties of plants have been recorded, out of which 200 are endemic and 1,300 do not occur in mainland India. So if any one of them are lost its lost for ever.
3.
The territory is home to about 225 species of
butterflies and
moths, including some of the larger and most spectacular of the world. Ten species are endemic to these Islands.
Mount Harriet National Park is one of the richest areas of butterfly and moth diversity on these Islands. Give a visit to Butterfly museum in Port Blair, one step inside and you will be taken to some other world.
4. India has very very rare places which are not touched much by human interventions, thus the many of these islands have very presitine natural enviornment. If we can safe guard them our future generation would be able to cheerish nature.
Now bombing any of those areas will create not only damage due to blasts, but also the sound pollution will scare of the habitats.
Frankly speaking, though andaman islands are lonely place with least human interaction, they are also the worst place to think of testing, because its natural adobe of those dont need humans in there life.
Tests like should be done on barren lands where there is no flora or fauna to get damaged.