TSA uses their own system for day to day operations. If given access to airport radios, that is up to the airport management.
We gave them two of our radios, but it was never used. They would call us via phone is they needed anything.
You have to remember prior to 9/11 that 99% of all airport security screenings where private contractors who utilitized whatever the company had in place, which was usually nothing to very little.
TSA came in doing their own thing, using the high portion of the VHF federal allocation. That is/was the standard.