Have you considered that the ground station is identifying themselves?
They are Virgin Sydney not Velocity Sydney. Similarly contracted airlines call Qantas Sydney if they use Qantas for ground handling. If you are talking licensing regs I assume you mean Part 61?
As far as licensing is concerned I don't know if ground people require a flight radiotelephony licence - they used to if I remember correctly but not sure these days - but they could call themselves "Big Sky base" if they wanted