Ok, I figured it out. In the VM configuration as accessed via VMWare vSphere Client (vCenter), the default behavior of a VM seems to be to cap the video memory at 4MB, which only allows so much resolution. I had to power down the VM, then use vSphere Client to change the video memory of the VM to support my local monitor resolution (1920×1200), which is just under 8MB according to their calculator widget.
Once I made that change, and booted the VM back up, NoMachine is able to automagically set the remote resolution (using xrandr or whatever) to support fullscreen on my local monitor. In fact, it works better than RDP, which forces me to reconnect to my remote machine to change the resolution as viewed locally.
The speed behind this protocol is really blazingly fast! It was definitely worth the effort to get it going vs X11RDP. But, I wish either the VMWare display driver, or xrandr, or NoMachine surfaced the reason better as to why the resolution wasn’t going any higher. Probably all of those things need to change, which means they won’t. If this phenomenon was documented in a FAQ or forum, then my first experience with NoMachine would have been a lot less painful.