NRAO refers to a collection of facilities around the world (well, really the US and Chile) that gather and analyze cosmic radio frequency signals for various scientific projects. The combination of data from many dishes can be interpolated to give you a higher fidelity observation than you would with the one dish alone.
The Very Large Array, by itself, can actually be “tuned” by moving their own dishes along railroad tracks to either expand or contract. That can make a virtual dish several km in diameter. However, by adding data from all of those above facilities can make a virtual dish thousands of km in diameter.
Each one of these observatories is also an independent facility in its own right, and I’m sure that most of the time, that’s what they’re doing. (ALMA in Chile is also part of the Event Horizon Telescope that took a picture of the black hole in M87 last year.)
Anyway, back to Flight Simulator. The release notes said they made NRAO in the United States, but clearly there’s no way they did all of those telescopes. Next time I login to MSFS, I’ll have to figure out what they actually built! (Unless someone here knows!)