GNSS is an umbrella term that covers both the US GPS system and the Russian Glonass satellite systems. RNAV has been around since before GNSS. It used signals from multiple radio navigation aids to create a waypoint. With the introduction of GNSS, aircraft navigation systems would use the satellite system as its primary data source and back it up with radio navigation aids.
What the note on the approach chart means is that you can’t fly the approach unless you have a valid GPS/GLONASS signal. You can’t fly it using radio navaid created waypoints.
The good news is, none of that matters in MSFS. You always have access to the GNSS satellite system. Any of the navigation systems you listed allow you to fly the approach.