Yes, it's true.
Guys:
Mike is right - Despite strong sales, GM has discontinued the 1987 GN grilles. Actually, it's but one of many important GN specific parts they've killed off in the past few months.
GN Grille
LH headlamp bezel
LH fender marker lamp
Wastegate solenoid
Radiator cooling fan
Cooling fan motor
Evap canister solenoid
EGR valve
Unlike in past years, once the part is discontinued - supplies all but vanish. GM must be selling off existing stocks prior to officially killing the part -- therefore when it goes obsolete there is no supply anywhere in the dealer network
You can probably find the grille at Kirbans, as I know they stocked them. However, like the wastegate solenoid (Kirban raised the price 4 fold after GM discontinued them) you should prepare for a big price tag.
I would strongly advise that if you need anything trim related for the GN that you buy it NOW. Don't wait around, because before long you'll be paying *crazy* prices on eBay.
Tom