The risk is with any conventional VOR receiver system, not just one with a KN72 inside.
The point is that the circuits driving the bar, the t/f flags, and the Invalid flags, are all substantially separate, and can thus fail separately. This is how it has been since day 1.
If this is a certification issue then VORs and NDBs and ILSs will be shut down too
I wrote it as a heads-up (as the Americans call it) because the flight training system maintains that if the Invalid flag is not showing, the instrument can be trusted, which is bollox.