Unix systems in their early days originally outputted to physical teletypewriters. Since macOS is a Unix system and is derived from NeXTSTEP and BSD, is this still possible in modern versions of macOS?
The term "physical terminal" and "teletypewriter" is quite broad. You're talking products evolved over decades - and thus varying in hardware, functionality, etc.
If you're asking whether you can take an old teletypewriter from the 60's or 70's and hook it up directly to your modern Mac - then the answer is no. Macs (as well as common, modern PCs) simply do not have the hardware interface for connecting to that machinery. Depending on the model of teletypewriter, the hardware interface can vary from very exotic circuits to something resembling an RS-232 serial interface.
However, if you can add some modern electronics and are willing to add or reconfigure software - then yes, it is definitely possible. It doesn't really have much to do with macOS being derived from NeXTSTEP or BSD though - as you could do the same on Linux or Windows for that matter.
Have a look at for example this fun hobby project connecting a really old teletype to a modern computer using a custom developed USB interface:
You might find this helpful:
Most of the rest of the links I found are quite old.