1) If you're in a one party consent state it is legal.
2) It being legal means jack
for you.
It's a huge deal to record management without their knowledge/consent in any company, including ours. One of my previous jobs in another life was with a different fortune 100 company (also strong union) where a few guys taped a voice activated tape recorder under a manager's chair. The tape failed and the recorder fell on the ground. Security came in and fingerprinted people and those 3 guys lost their jobs. The "ringleader" didn't get his job back. The union got the other two who were along for the ride their jobs back after 60 day suspensions with no backpay.