Kseniiya, your point of other subtle language oppression is interesting. There is a school of thought called subalternity under post-colonialism. It applies broadly to all classes of people in all parts of the world who are discriminated against or oppressed in one or more ways, but under linguistics it refers to the ethnic languages which are ignored, disfavored or even actively suppressed by the dominant powers, whether colonial or otherwise. In India you can see this in the prevalence of the language of the Brits as the definitive ticket to better livelihood and social position. The British colonials had such a policy, first set out by Thomas Macaulay. By the time they left, the thing had gathered enough momentum to be past the tipping point and be self sustaining.
But that apart, it can also be seen in the general neglect (willful or otherwise) of certain "subaltern" languages such as the many tribal languages across India. Most are not in immediate danger of extinction, mainly because even tiny percentages translate to several millions in a country of 1.37 billion. At the same time, nor do they serve any practical purpose in life except keeping certain traditions alive. They are certainly no help in terms of livelihood or social position, and the writing is on the wall: I see many people from such ethnic groups who can barely speak their native languages, particularly those who have migrated outside their native rural settings.