This explains why MSG called out the NYSLA - https://www.forbes.com/sites/justinbirnbaum/2022/12/07/madis...
Notice that there is no claim here that it is a safety issue.
If MSG fears certain employees may reveal things it does not want known, it should constrain those employees from contact with the public within its venues.
To me this screams "MSG is doing illegal/contract breaking shit"