Are you an electrician or do you work for said company? Makes a difference because right now it's a different set of rules and/or additional rules that may be made by the POCO for employees. I think next year lineman or meter techs and electricians will be following similar rules. Next year everyone will have to wear gear that is arc rated for the location. Right now that is not the case. You can see someone working on bushings of a transformer with rubber gloves, glasses, and light FR while an electrician is required to be in a bomb suit in similar locations.
I don't think there are any extra OSHA rules for working on a meter trough. Where I am only a face shield, glasses, minimum FR, and rubber gloves, are required when working in a meter trough over 240v including 240v three phase. No face shield 240 single phase and under. Those are company rules. There are going to be new OSHA arc rating rules next year, but they are vague right now I think.
Unless you are an employee of the company, it just sounds like they are using it as an excuse to not let anyone access meter troughs besides company reps.