Who's presuming? Swartz was remarkably vocal about his aspirations for the internet, and I definitely don't remember hearing him say that the future we ought to fight for is one where APIs wrapping user-generated content are only accessible to institutions with deep pockets.
It would be incredibly surprising for Swartz to have supported the kind of bait-and-switch tactics Reddit is employing here.
[1]: https://en.wikipedia.org/wiki/Guerilla_Open_Access_Manifesto