Thank you for the information and your question. I am sorry to read about your situation. However, unless you have a contract that locks you into your position or location, or there is a company policy that gives you some sort of election or seniority rights, your employer is free to set and change the terms and conditions of your employment as they deem appropriate. The only other restriction on their ability to do what you described is that they cannot target a particular employee for an adverse
employment action simply because that employee is a member of a protected class under employment discrimination
If you believe you fall within one of the exceptions that I mentioned, you will want to file a formal complaint with your HR and allow them to try to resolve it. Then if they can't, you will want to sit down with a local employment law
attorney and discuss your case to see if there is any possible legal recourse.
All that said, I don't see anything that is per se "adverse" under the legal definition. Certainly if you are demoted, or must commute many more miles than the group that is going to the other location, that would be adverse. However, not going with your regular unit, absent a demotion or the commute issue I mentioned is not considered adverse. That doesn't mean you can't discuss your concerns with your boss and HR, it just means you really aren't likely to have any legal recourse, since in office politics, although unprofessional, is not illegal. Again that is assuming the other exceptions don't apply here.
Please let me know if you need any clarification. I would be glad to assist you further if I can.