There is nothing wrong for management to communicate with its employees to follow one pattern of language as a medium, and I welcome that. If every individual speaks in their language of choice, then uniformity is not maintained.
When office circulars, inter-office correspondences, and office orders are all in English, why not insist on English as the language in a common platform? When someone is habituated to speaking in Hindi, Tamil, or another vernacular, they may continue communicating in the same way when others are nearby without realizing that the other person may not understand their language. This could give the impression to a third person that these two individuals want to hide something from them, although that may not be the case.
Furthermore, every language has its own accent. You cannot imagine something in Hindi and convey it in English. If someone practices speaking in Tamil at the office and suddenly needs to switch to English, they may end up speaking "Tanglish," struggling to use the correct vocabulary. While this may be acceptable within a small group, imagine if such individuals need to present to an elite group of people from abroad – they represent the company, not just themselves.
Additionally, why must someone view this as a "forceful" activity? Practice makes perfect. One can see this situation as a positive opportunity to sharpen and hone their English speaking skills. It all depends on the individual's mental framework.
V. Balaji