Yeah, NOTAMs come into play when the shit hits the fan; radios are dead and you can't reach the tower kinda thing, but in that case just be sure you declared emergency, then they (probably) won't get you much for landing on a closed runway or a taxiway.
They have backup transmitters and if everything fails (tower evacuation has happened) you talk to the overlying approach / tracon / center frequencies to check. And then after that, land anyway and self announce positions for other traffic.
It's basically the same as landing at an airport that doesn't have a tower. Happens every day at hundreds of airports.
