There are so many airports in MSFS that are out of date.
For example UTAA Ashgabat (main international airport of capital city) is missing a runway. Navigraph data will allow you to fly an “ILS” to a nonexistent runway.
It would increase the value of navigraph data if the airports were always matching.
According to MS, there are 37,000 airports. If 1h per airport were allocated this would equal 18.5 person-years. I’m not sure how long it actually takes to program a large airport but there are many small ones and perhaps you could start with simply “touching up” existing airport to at least make sure the runways and taxiways are up to date.