That is, essentially, what we're doing. Renaming things, reworking the fiction.
Apocalypse World, as it stands, has a particular fiction going on, and that is a post-apocalyptic setting on what is, essentially, Earth, 50 or so years after the maelstrom ended the Golden Age, or whatever ended the Golden Age created the maelstrom. The setting is flexible, sure, but still limited to planetside.
To take it into space, you need a few things: ships, rules for ships, a different setting history, a definite change to the fiction of each class. "Angel" works in the vanilla AW setting, because of the kind of culture that arises in an "After The End" situation. It doesn't work quite as well in the Space Age, though you could use it if you wanted to. In our group, we wanted a different fiction, but the core of the game works just as well within the new setting, with a few minor changes, and we didn't want a different game, we just wanted a different fiction surrounding it.
Consider it like a campaign module for any tabletop RPG. We aren't mucking with the core mechanics, we're putting up a new setting with a few setting specific things, and anyone can play with it as they please.
In addition, you can consider this the foundation. This is the quick and dirty hack, the rough draft. More stuff will be added as we get around to it, and maybe more/different moves will put to the classes as we figure out what still works and what can be changed.