Empty Room Full of Promise

I've seen a couple posts about empty rooms, another topic of recurring debate. One blogger (don't recall who) mentioned that empty rooms in a megadungeon exist for the same reason as "empty" hexes in a wilderness hexcrawl. JD Jarvis says that empty rooms shouldn't stay empty, and that they exist to provide tension, building up to the moment when the room behind that door turns out not to be empty at all.

All good points, but here's something else to consider. Look at this room:

23. Barren Room, locked door in north, stairs down to level 2.

Is that room empty? Not at all. It contains a locked door and a staircase. At the bare minimum, the room's structure provides the necessary interactivity to make the room worth looking at. Now, empty rooms with empty doorways would provide much less structure, especially if there aren't even any other exits. The tendency of some designers to use linear dungeon structures is what makes empty rooms more boring. If you had a hundred-foot long hallway that extends south from the dungeon entrance, then turns east, and there were four doorways on the west wall of the hallway that each lead to a 20-foot square room with no other exits, it would be pretty boring if all the rooms were empty. Put a locked door on them, at the very least, and  a fifth locked door that leads to another corridor to a more interesting section of dungeon. And put a room with a monster around that east turn, so that the monster can investigate any sounds of doors being busted down.

Structure isn't the only way to make an empty room interactive. Let's say that same hundred-foot corridor with four rooms to the west is a crypt area. Each room contains a sealed sarcophagus. One room has some treasure in the sarcophagus. Another has the cliche skeleton that comes to life when disturbed. The other, empty rooms thus become less empty simply because of the context: the players will just know you are going to have something jump out of one of those sarcophagi, but there might be treasure in one... opening each normal sarcophagus and riffling through each normal corpse's belongings is thus tense, even though technically there's "nothing" in half the rooms. But it's the kind of nothing that could be something.