There are easier ways to spy on your employees. This is not cost-effective.
I use Zoom for work now and each call can be several gigabytes large, depending on resolution of shared materials and a few other factors. If you want to save that kind of stuff long term, you have to pay to keep it somewhere. If you multiply several gigabytes over a few dozen calls a day, you’re going to end up with terabytes of garbage you need to store. Zoom also informs you of when a recording is starting and active, offering for you to leave the call or otherwise implicitly agree to being recorded. You have to pay for all these things because there’s a significant amount of processing power involved. It’s not like it’s free to run facial recognition and speech recognition.
When I did contract work for Apple support, the spying was way more efficient than just listening to my calls. My supervisor could literally always see my monitor through the chat program we had installed. There’s all kinds of remote software for things like this. If an admin wants to see you misuse your equipment, they have easier ways of finding out than sifting through calls to find wrongthink.