My employer is investigating complaints and told me during my interview that I can’t talk to my coworkers is this legal?

Transcript:

Under the National Labor Relations Act, you as an employee have the abilities to engage in concerted activity. Meaning that you have the right to discuss certain terms and conditions of your employment with your coworkers and to be free to be able to exercise those rights under the National Labor Relations Act. There are some sorts of claims and some sorts of situations where you may be obligated to keep those confidential depending on what they are. If you have questions about that, it’s a good idea to seek counsel from an employment lawyer who can advise you of what your rights and obligations might be.