That does not make it the 'real name' and it's not for a government to decree how foreign languages in foreign countries should pronounce the names of local cities.

In this case it is really just a political move to push back against colonial times by changing the English names of Indian cities (not only Bangalore) to strict local orthography. The fact that English is used as a common language in India may play a role in that push because they probably see a need to define names in English (which is ironic).

It also depends on the language. China also did that for Beijing, Guangzhou, etc. It worked in English but e.g. in French nobody cared and the 'French' names are still used, the same largely goes for the name of Indian cities.