In the rules "Enter Function" specifically describes the Enter text on a room card. I initially interpreted the language quoted in the OP as meaning that NPCs trigger Enter Functions. But this is not necessarily true--the syntax could just as easily mean that the NPC ignores all relevant item card effects (ones that effect NPCs) and moves immediately to the next room if able.
A perusal or the rules suggests this is the case:
Enter Function: Some rooms contain elements that react when operatives enter them. Each time an operative enters a room with an Enter function, that player immediately resolves that function.
Enter Functions relate to Operatives only.
I'm not sure if the NPC would still perform a "When you enter the room" action. The "immediately" bit is the part that makes me question that, though--Enter Function refers strictly to Room Cards.