Here's the text from Moldvay pp B3-B4, B19, B23, B51-B52:Which still boils down to "the purpose of prep being to give the GM something to say"; even more so when you include the GM's descriptions of those areas the PCs are exploring.
It is the DM's job to prepare the setting for each adventure before the game begins. The setting is called a dungeon since most adventures take place in underground caverns or stone rooms beneath old ruins or castles. The dungeon is carefully mapped on paper (usually graph paper). A dungeon may be designed by the DM, or may be a purchased dungeon . . . (called a dungeon module). Whether creating a new dungeon or carefully studying a module, the DM must be willing to spend more time in preparation than the players. . . .
At the start of the game, the players enter the dungeon and the DM describes what the characters can see. One player should draw a map from the DM's descriptions; that player is called the mapper. As the player characters move further into the dungeon, more and more of the dungeon is mapped. Eventually, the DM's map and the players' map will look more or less alike. . . .
As details of the dungeon are revealed, the player characters will meet "monsters" which they will have to avoid, talk to, or fight. A monster is any animal, person, or supernatural creature that is not a player character. . . .
When the players have rolled up their characters and bought their equipment, the DM will describe the background of the adventure. . . .
The DM will find it useful to make a list of monster encounters before the adventure starts, noting their Number Appearing, Armor Class, hit points, and so forth. Having this information prepared before the adventure will speed play during the game. These monsters will often have a reason for being in the dungeon (such as looking for food or a special magic item, carrying a message, and so forth).
Before players can take their characters on adventures into dungeons, the DM must either create a dungeon or draw its map, or become familiar with one of TSR's dungeon modules. . . .
This section gives a step-by-step guide to creating a dungeon. . . .
A. Choose a scenario . . .
B. Decide on a setting . . .
C. Decide on special monsters to be used . . .
D. Draw the map of the dungeon . . .
E. Stock the dungeon . . .
F. Filling in final details
At the start of the game, the players enter the dungeon and the DM describes what the characters can see. One player should draw a map from the DM's descriptions; that player is called the mapper. As the player characters move further into the dungeon, more and more of the dungeon is mapped. Eventually, the DM's map and the players' map will look more or less alike. . . .
As details of the dungeon are revealed, the player characters will meet "monsters" which they will have to avoid, talk to, or fight. A monster is any animal, person, or supernatural creature that is not a player character. . . .
When the players have rolled up their characters and bought their equipment, the DM will describe the background of the adventure. . . .
The DM will find it useful to make a list of monster encounters before the adventure starts, noting their Number Appearing, Armor Class, hit points, and so forth. Having this information prepared before the adventure will speed play during the game. These monsters will often have a reason for being in the dungeon (such as looking for food or a special magic item, carrying a message, and so forth).
Before players can take their characters on adventures into dungeons, the DM must either create a dungeon or draw its map, or become familiar with one of TSR's dungeon modules. . . .
This section gives a step-by-step guide to creating a dungeon. . . .
A. Choose a scenario . . .
B. Decide on a setting . . .
C. Decide on special monsters to be used . . .
D. Draw the map of the dungeon . . .
E. Stock the dungeon . . .
F. Filling in final details
Nowhere does this talk about the GM having interesting things to say. It mentions the GM describing things, but that is only part of the purpose of prep. It seems pretty clear that the main goal of prep is to create a mapped and keyed dungeon that the GM then reveals to the players during play, based on the players' play of their PCs as dungeon adventurers. A secondary goal of prep is to have the stats for monsters and NPCs ready-to-hand in case of combat.
Preparing a front in Apocalypse World somewhat resembles steps A and C. It does not have any analogue to D, E or F. And the analogue to step A, in preparing a front, is very different from the Moldvay Basic step. Molday Basic does not require the GM to establish clocks or stakes questions or agendas/dark futures. Because it is a game of exploring a dungeon, not a game of finding out what happens to the characters. Here is the AW text on "Why to play" (pp 17-17):
One: Because the characters are [very] hot.
Two: Because hot as they are, the characters are best and hottest when you put them together. Lovers, rivals, friends, enemies, blood and sex - that’s the good [stuff].
Three: Because the characters are together against a horrific world. They’re carving out their little space of hope and freedom in the filth and violence, and they’re trying to hold onto it. Do they have it in them? What are they going to have to do to hold it together? Are they prepared, tough enough, strong enough and willing?
Four: Because they’re together, sure, but they’re desperate and they’re under a lot of pressure. If there’s not enough to go around (and is there ever?), who’ll stick together and who’ll turn on whom? Who do you trust, and who should you trust, and what if you get it wrong?
Five: Because there’s something really wrong with the world, and I don’t know what it is. The world wasn’t always like this, blasted and brutal. There wasn’t always a psychic maelstrom howling just out of your perception, waiting for you to open your brain so that it can rush in. Who [messed] the world up, and how? Is there a way back? A way forward? If anybody’s going to ever find out, it’s you and your characters.
That’s why.
Two: Because hot as they are, the characters are best and hottest when you put them together. Lovers, rivals, friends, enemies, blood and sex - that’s the good [stuff].
Three: Because the characters are together against a horrific world. They’re carving out their little space of hope and freedom in the filth and violence, and they’re trying to hold onto it. Do they have it in them? What are they going to have to do to hold it together? Are they prepared, tough enough, strong enough and willing?
Four: Because they’re together, sure, but they’re desperate and they’re under a lot of pressure. If there’s not enough to go around (and is there ever?), who’ll stick together and who’ll turn on whom? Who do you trust, and who should you trust, and what if you get it wrong?
Five: Because there’s something really wrong with the world, and I don’t know what it is. The world wasn’t always like this, blasted and brutal. There wasn’t always a psychic maelstrom howling just out of your perception, waiting for you to open your brain so that it can rush in. Who [messed] the world up, and how? Is there a way back? A way forward? If anybody’s going to ever find out, it’s you and your characters.
That’s why.
Giving the GM interesting things to say within the context of play, in which - as a matter of technical procedure - all the GM does is either call on the players to roll their moves, or else speak GM moves, is the sole purpose of AW prep. There is no analogue of the players' map coming to more and more closely resemble the GM's map, and hence no part of prep that corresponds to that aspect of Basic D&D prep.
And here's another striking point of contrast: in Basic, the players roll up their PCs and choose their equipment, and then the GM describes the initial situation. In AW, the players build their PCs and then the first session is played, and out of that certain relationships, threats, trajectories etc emerge - and then the GM preps their first front, so they have things that are interesting to say in the context that the first session has established.
Saying that these all boil down to the same thing just seems like it is intended to elide all differences in RPGing.