I'm surprised it came up with that - did it say deluxe room? The AKL does have rooms that sleep five - but no standard rooms. The deluxe rooms have either two queens (only sleeping 4), or one queen, bunk beds, and a day bed. These rooms do comfortably sleep five - we've stayed there twice now! The deluxe rooms are on the 5th and 6th floors (6th is concierge only). You can reserve these with or without concierge service, but they are more expensive than the regular AKL rooms.
Basically, any of your deluxes will sleep five - at AKL or WL, you will need to get the deluxe room. The Contemporary, Poly and Grand Floridian have nice big rooms with 2 queens and a twin sized day bed. I haven't stayed at the Epcot resorts yet, but the YC/BC have two queens and a day bed as well - while the BWI has two queens with a small child sized day bed.
If your budget doesn't stretch to a deluxe, the POR - Alligater Bayou has rooms with two doubles and a child sized trundle bed that sleep five.
There is also FT. Wilderness. The cabins there sleep six - bunk beds and a double in the bedroom, and a double sleep sofa in the living room.
Happy planning!