By reading the heading of the post, one feels that the HR was removed from the WhatsApp group or what. Nevertheless, on reading the post one gets a clarity.
When the person was removing from the WA group, it showed that he had become persona non grata. However, before withholding his salary, HR should have communicated clearly what was the reason for holding the salary. Anyway, as of now, let that employee put up application to the Director or MD of the company seeking clarification. That is the first step.
It is obvious that such sudden actions point Howards what is waiting in the wings for you.
Before axe falls on you, try to find out what has gone wrong and if it is unjust intention on the part of the management, take up with the right authority to resolve this before it is too late.